new plotter

android-app-core/src/main/java/org/solovyev/android/AndroidUtils2.java

@@ -6,7 +6,9 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
+import android.os.Build;
 import android.util.Log;
+import android.view.MotionEvent;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.File;
@@ -21,6 +23,9 @@ import java.io.IOException;
  */
 public final class AndroidUtils2 {
 
+    @NotNull
+    private static final boolean AT_LEAST_API_5 = Build.VERSION.SDK_INT >= 5;
+
     private AndroidUtils2() {
         throw new AssertionError();
     }
@@ -97,4 +102,16 @@ public final class AndroidUtils2 {
 
         return null;
     }
+
+    public static int getPointerCountFromMotionEvent(@NotNull MotionEvent event) {
+        return AT_LEAST_API_5 ? event.getPointerCount() : 1;
+    }
+
+    public static float getXFromMotionEvent(@NotNull MotionEvent event, int pointer) {
+        return AT_LEAST_API_5 ? event.getX(pointer) : 0;
+    }
+
+    public static float getYFromMotionEvent(@NotNull MotionEvent event, int pointer) {
+        return AT_LEAST_API_5 ? event.getY(pointer) : 0;
+    }
 }

android-app/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java

@@ -63,7 +63,6 @@ public class CalculatorActivity extends SherlockFragmentActivity implements Shar
             activityHelper.addTab(this, CalculatorFragmentType.variables, null, R.id.main_second_pane);
             activityHelper.addTab(this, CalculatorFragmentType.functions, null, R.id.main_second_pane);
             activityHelper.addTab(this, CalculatorFragmentType.operators, null, R.id.main_second_pane);
-            activityHelper.addTab(this, CalculatorFragmentType.plotter_functions, null, R.id.main_second_pane);
             activityHelper.addTab(this, CalculatorPlotActivity.getPlotterFragmentType(), null, R.id.main_second_pane);
             activityHelper.addTab(this, CalculatorFragmentType.faq, null, R.id.main_second_pane);
         } else {

android-app/src/main/java/org/solovyev/android/calculator/CalculatorFragmentType.java

@@ -13,7 +13,7 @@ import org.solovyev.android.calculator.math.edit.CalculatorFunctionsFragment;
 import org.solovyev.android.calculator.math.edit.CalculatorOperatorsFragment;
 import org.solovyev.android.calculator.math.edit.CalculatorVarsFragment;
 import org.solovyev.android.calculator.matrix.CalculatorMatrixEditFragment;
-import org.solovyev.android.calculator.plot.CalculatorArityPlotFragment;
+import org.solovyev.android.calculator.plot.CalculatorPlotFragment;
 import org.solovyev.android.calculator.plot.CalculatorPlotFunctionSettingsActivity;
 import org.solovyev.android.calculator.plot.CalculatorPlotFunctionsActivity;
 
@@ -32,7 +32,7 @@ public enum CalculatorFragmentType {
     variables(CalculatorVarsFragment.class, R.layout.vars_fragment, R.string.c_vars),
     functions(CalculatorFunctionsFragment.class, R.layout.math_entities_fragment, R.string.c_functions),
     operators(CalculatorOperatorsFragment.class, R.layout.math_entities_fragment, R.string.c_operators),
-    plotter(CalculatorArityPlotFragment.class, R.layout.cpp_plot_fragment, R.string.c_graph),
+    plotter(CalculatorPlotFragment.class, R.layout.cpp_plot_fragment, R.string.c_graph),
 
 	// todo serso: strings
 	plotter_functions(CalculatorPlotFunctionsActivity.CalculatorPlotFunctionsFragment.class, R.layout.cpp_plot_functions_fragment, R.string.c_graph),

android-app/src/main/java/org/solovyev/android/calculator/plot/AbstractCalculatorPlotFragment.java

@@ -393,6 +393,13 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
         public PlotBoundaries() {
         }
 
+        private PlotBoundaries(double xMin, double xMax, double yMin, double yMax) {
+            this.xMin = xMin;
+            this.xMax = xMax;
+            this.yMin = yMin;
+            this.yMax = yMax;
+        }
+
         public PlotBoundaries(@NotNull XYMultipleSeriesRenderer renderer) {
             this.xMin = renderer.getXAxisMin();
             this.yMin = renderer.getYAxisMin();
@@ -400,6 +407,11 @@ public abstract class AbstractCalculatorPlotFragment extends CalculatorFragment
             this.yMax = renderer.getYAxisMax();
         }
 
+        @NotNull
+        public static PlotBoundaries newInstance(double xMin, double xMax, double yMin, double yMax) {
+            return new PlotBoundaries(xMin, xMax, yMin, yMax);
+        }
+
         public double getXMin() {
             return xMin;
         }

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorGraph2dView.java

@@ -22,11 +22,30 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
-public class Graph2dViewNew extends View implements GraphView {
+public class CalculatorGraph2dView extends View implements GraphView {
 
-    // view width and height
+    /*
-    private int width;
+    **********************************************************************
-    private int height;
+    *
+    *                           CONSTANTS
+    *
+    **********************************************************************
+    */
+
+    private static final float TICKS_COUNT = 15;
+    public static final int TICK_SIZE_PXS = 3;
+
+    /*
+    **********************************************************************
+    *
+    *                           FIELDS
+    *
+    **********************************************************************
+    */
+
+    // view width and height in pixels
+    private int widthPxs;
+    private int heightPxs;
 
     @NotNull
     private final Matrix matrix = new Matrix();
@@ -52,8 +71,11 @@ public class Graph2dViewNew extends View implements GraphView {
     @NotNull
     private List<GraphData> graphs = new ArrayList<GraphData>(graphViewHelper.getFunctionPlotDefs().size());
 
+    // current position of camera in graph coordinates
     private float x0;
     private float y0;
+
+    // graph width in function units (NOT screen pixels)
     private float graphWidth = 20;
 
     private float lastXMin;
@@ -76,12 +98,12 @@ public class Graph2dViewNew extends View implements GraphView {
     @NotNull
     private Scroller scroller;
 
-    public Graph2dViewNew(Context context, AttributeSet attrs) {
+    public CalculatorGraph2dView(Context context, AttributeSet attrs) {
         super(context, attrs);
         init(context);
     }
 
-    public Graph2dViewNew(Context context) {
+    public CalculatorGraph2dView(Context context) {
         super(context);
         init(context);
     }
@@ -94,13 +116,13 @@ public class Graph2dViewNew extends View implements GraphView {
         paint.setAntiAlias(false);
         textPaint.setAntiAlias(true);
 
-        width = this.getWidth();
+        widthPxs = this.getWidth();
-        height = this.getHeight();
+        heightPxs = this.getHeight();
     }
 
     @NotNull
     public Bitmap captureScreenshot() {
-        final Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
+        final Bitmap result = Bitmap.createBitmap(widthPxs, heightPxs, Bitmap.Config.RGB_565);
         Canvas canvas = new Canvas(result);
         onDraw(canvas);
         return result;
@@ -141,25 +163,6 @@ public class Graph2dViewNew extends View implements GraphView {
         invalidate();
     }
 
-    public void onVisibilityChanged(boolean visible) {
-    }
-
-    public void onZoom(boolean zoomIn) {
-        if (zoomIn) {
-            if (canZoomIn()) {
-                graphWidth /= 2;
-                invalidateGraphs();
-            }
-        } else {
-            if (canZoomOut()) {
-                graphWidth *= 2;
-                invalidateGraphs();
-            }
-        }
-        zoomController.setZoomInEnabled(canZoomIn());
-        zoomController.setZoomOutEnabled(canZoomOut());
-    }
-
     public void onResume() {
     }
 
@@ -172,8 +175,8 @@ public class Graph2dViewNew extends View implements GraphView {
     }
 
     protected void onSizeChanged(int w, int h, int ow, int oh) {
-        width = w;
+        widthPxs = w;
-        height = h;
+        heightPxs = h;
         clearAllGraphs();
         // points = new float[w+w];
     }
@@ -183,7 +186,7 @@ public class Graph2dViewNew extends View implements GraphView {
             return;
         }
         if (scroller.computeScrollOffset()) {
-            final float scale = graphWidth / width;
+            final float scale = graphWidth / widthPxs;
             x0 = scroller.getCurrX() * scale;
             y0 = scroller.getCurrY() * scale;
             if (!scroller.isFinished()) {
@@ -259,7 +262,7 @@ public class Graph2dViewNew extends View implements GraphView {
             graph.push(xMin, eval(function, xMin));
         }
 
-        final float scale = width / graphWidth;
+        final float scale = getRatio();
         final float maxStep = 15.8976f / scale;
         final float minStep = .05f / scale;
         float ythresh = 1 / scale;
@@ -364,20 +367,20 @@ public class Graph2dViewNew extends View implements GraphView {
         }
     }
 
-    private static final float NTICKS = 15;
+    private static float getStep(float width) {
-
-    private static float stepFactor(float w) {
         float f = 1;
-        while (w / f > NTICKS) {
+        while (width / f > TICKS_COUNT) {
             f *= 10;
         }
-        while (w / f < NTICKS / 10) {
+        
+        while (width / f < TICKS_COUNT / 10) {
             f /= 10;
         }
-        float r = w / f;
+
-        if (r < NTICKS / 5) {
+        final float r = width / f;
+        if (r < TICKS_COUNT / 5) {
             return f / 5;
-        } else if (r < NTICKS / 2) {
+        } else if (r < TICKS_COUNT / 2) {
             return f / 2;
         } else {
             return f;
@@ -387,13 +390,14 @@ public class Graph2dViewNew extends View implements GraphView {
     private static StringBuilder b = new StringBuilder();
     private static char[] buf = new char[20];
 
-    private static StringBuilder format(final float value) {
+    @NotNull
-        int pos = 0;
+    private static CharSequence formatTick(final float tickValue) {
+        /*int pos = 0;
         boolean addDot = false;
 
-        final boolean negative = value < 0;
+        final boolean negative = tickValue < 0;
 
-        int absValue = Math.round(Math.abs(value) * 100);
+        int absValue = Math.round(Math.abs(tickValue) * 100);
         for (int i = 0; i < 2; ++i) {
             int digit = absValue % 10;
             absValue /= 10;
@@ -418,17 +422,18 @@ public class Graph2dViewNew extends View implements GraphView {
         b.setLength(0);
         b.append(buf, 0, pos);
         b.reverse();
-        return b;
+        return b;*/
+        return Float.toString(tickValue);
     }
 
-    private void drawGraph(Canvas canvas) {
+    private void drawGraph(@NotNull Canvas canvas) {
+        final float graphHeight = getGraphHeight();
 
         final float xMin = getXMin();
         final float xMax = getXMax(xMin);
 
-        float graphHeight = graphWidth * height / width;
+        final float yMin = getYMin(graphHeight);
-        float yMin = y0 - graphHeight / 2;
+        final float yMax = getYMax(graphHeight, yMin);
-        float yMax = yMin + graphHeight;
 
         if (yMin < lastYMin || yMax > lastYMax) {
             float halfGraphHeight = graphHeight / 2;
@@ -445,26 +450,21 @@ public class Graph2dViewNew extends View implements GraphView {
         paint.setAntiAlias(false);
         paint.setStyle(Paint.Style.STROKE);
 
-        final float scale = width / graphWidth;
+        final float ratio = getRatio();
 
-        float x0 = -xMin * scale;
+        float x0px = -xMin * ratio;
-        boolean drawYAxis = true;
+        if (x0px < 25) {
-        if (x0 < 25) {
+            x0px = 25;
-            x0 = 25;
+        } else if (x0px > widthPxs - 3) {
-            // drawYAxis = false;
+            x0px = widthPxs - 3;
-        } else if (x0 > width - 3) {
-            x0 = width - 3;
-            // drawYAxis = false;
-        }
-        float y0 = yMax * scale;
-        if (y0 < 3) {
-            y0 = 3;
-        } else if (y0 > height - 15) {
-            y0 = height - 15;
         }
 
-        final float tickSize = 3;
+        float y0px = yMax * ratio;
-        final float y2 = y0 + tickSize;
+        if (y0px < 3) {
+            y0px = 3;
+        } else if (y0px > heightPxs - 15) {
+            y0px = heightPxs - 15;
+        }
 
 
         {
@@ -473,29 +473,41 @@ public class Graph2dViewNew extends View implements GraphView {
             paint.setPathEffect(new DashPathEffect(new float[]{5, 10}, 0));
             paint.setColor(graphViewHelper.getFunctionViewDef().getGridColor());
 
-            float step = stepFactor(graphWidth);
-            // Calculator.log("width " + gwidth + " step " + step);
-            float v = ((int) (xMin / step)) * step;
             textPaint.setColor(graphViewHelper.getFunctionViewDef().getAxisLabelsColor());
             textPaint.setTextSize(12);
             textPaint.setTextAlign(Paint.Align.CENTER);
-            float stepScale = step * scale;
+
-            for (float x = (v - xMin) * scale; x <= width; x += stepScale, v += step) {
+            final float step = getStep(graphWidth);
-                canvas.drawLine(x, 0, x, height, paint);
+
-                if (!(-.001f < v && v < .001f)) {
+            // round xMin and init first tick
-                    StringBuilder b = format(v);
+            float tick = ((int) (xMin / step)) * step;
-                    canvas.drawText(b, 0, b.length(), x, y2 + 10, textPaint);
+
+            final float y2 = y0px + TICK_SIZE_PXS;
+
+            float stepPxs = step * ratio;
+            for (float xPxs = (tick - xMin) * ratio; xPxs <= widthPxs; xPxs += stepPxs, tick += step) {
+                // draw grid line
+                canvas.drawLine(xPxs, 0, xPxs, heightPxs, paint);
+
+                if (Math.abs(tick) >= .001f) {
+                   final CharSequence tickLabel = formatTick(tick);
+
+                    // draw tick label
+                    canvas.drawText(tickLabel, 0, tickLabel.length(), xPxs, y2 + 10, textPaint);
                 }
             }
 
-            final float x1 = x0 - tickSize;
+            final float x1 = x0px - TICK_SIZE_PXS;
-            v = ((int) (yMin / step)) * step;
+            tick = ((int) (yMin / step)) * step;
             textPaint.setTextAlign(Paint.Align.RIGHT);
-            for (float y = height - (v - yMin) * scale; y >= 0; y -= stepScale, v += step) {
+            for (float y = heightPxs - (tick - yMin) * ratio; y >= 0; y -= stepPxs, tick += step) {
-                canvas.drawLine(0, y, width, y, paint);
+                canvas.drawLine(0, y, widthPxs, y, paint);
-                if (!(-.001f < v && v < .001f)) {
+
-                    StringBuilder b = format(v);
+                if (Math.abs(tick) >= .001f) {
-                    canvas.drawText(b, 0, b.length(), x1, y + 4, textPaint);
+                    final CharSequence tickLabel = formatTick(tick);
+
+                    // draw tick label
+                    canvas.drawText(tickLabel, 0, tickLabel.length(), x1, y + 4, textPaint);
                 }
             }
 
@@ -506,17 +518,15 @@ public class Graph2dViewNew extends View implements GraphView {
             // AXIS
 
             paint.setColor(graphViewHelper.getFunctionViewDef().getAxisColor());
-            if (drawYAxis) {
+            canvas.drawLine(x0px, 0, x0px, heightPxs, paint);
-                canvas.drawLine(x0, 0, x0, height, paint);
+            canvas.drawLine(0, y0px, widthPxs, y0px, paint);
-            }
-            canvas.drawLine(0, y0, width, y0, paint);
         }
 
 
         matrix.reset();
         matrix.preTranslate(-this.x0, -this.y0);
-        matrix.postScale(scale, -scale);
+        matrix.postScale(ratio, -ratio);
-        matrix.postTranslate(width / 2, height / 2);
+        matrix.postTranslate(widthPxs / 2, heightPxs / 2);
 
         paint.setAntiAlias(false);
 
@@ -546,18 +556,78 @@ public class Graph2dViewNew extends View implements GraphView {
         lastXMin = xMin;
     }
 
+    /*
+    **********************************************************************
+    *
+    *                           BOUNDARIES
+    *
+    **********************************************************************
+    */
+
+    // X
+
+    public float getXMin() {
+        return x0 - graphWidth / 2;
+    }
+
     private float getXMax(float minX) {
         return minX + graphWidth;
     }
 
-    private float getXMax() {
+    public float getXMax() {
         return getXMax(getXMin());
     }
 
-    private float getXMin() {
+    // Y
-        return x0 - graphWidth / 2;
+
+    @Override
+    public float getYMin() {
+        return getYMin(getGraphHeight());
     }
 
+
+    public float getYMin(float graphHeight) {
+        return y0 - graphHeight / 2;
+    }
+
+    @Override
+    public float getYMax() {
+        final float graphHeight = getGraphHeight();
+        return getYMax(graphHeight, getYMin(graphHeight));
+    }
+
+    public float getYMax(float graphHeight, float yMin) {
+        return yMin + graphHeight;
+    }
+
+    private float getGraphHeight() {
+        return graphWidth * getAspectRatio();
+    }
+
+    private float getRatio() {
+        if (graphWidth != 0) {
+            return widthPxs / graphWidth;
+        } else {
+            return 0;
+        }
+    }
+
+    private int getAspectRatio() {
+        if (widthPxs != 0) {
+            return heightPxs / widthPxs;
+        } else {
+            return 0;
+        }
+    }
+
+    /*
+    **********************************************************************
+    *
+    *                           ZOOM
+    *
+    **********************************************************************
+    */
+
     private boolean canZoomIn() {
         return true;
     }
@@ -566,15 +636,40 @@ public class Graph2dViewNew extends View implements GraphView {
         return true;
     }
 
-    private void invalidateGraphs() {
+    public void onVisibilityChanged(boolean visible) {
-        clearAllGraphs();
-        lastYMin = lastYMax = 0;
-        invalidate();
     }
 
+    public void onZoom(boolean zoomIn) {
+        if (zoomIn) {
+            if (canZoomIn()) {
+                graphWidth /= 2;
+                invalidateGraphs();
+            }
+        } else {
+            if (canZoomOut()) {
+                graphWidth *= 2;
+                invalidateGraphs();
+            }
+        }
+        zoomController.setZoomInEnabled(canZoomIn());
+        zoomController.setZoomOutEnabled(canZoomOut());
+    }
+
+    /*
+    **********************************************************************
+    *
+    *                           TOUCH
+    *
+    **********************************************************************
+    */
+
     @Override
-    public boolean onTouchEvent(MotionEvent event) {
+    public boolean onTouchEvent(@NotNull MotionEvent event) {
-        return touchHandler != null ? touchHandler.onTouchEvent(event) : super.onTouchEvent(event);
+        boolean handled = touchHandler.handleTouchEvent(event);
+        if (!handled) {
+            handled = super.onTouchEvent(event);
+        }
+        return handled;
     }
 
     public void onTouchDown(float x, float y) {
@@ -598,9 +693,11 @@ public class Graph2dViewNew extends View implements GraphView {
     }
 
     public void onTouchUp(float x, float y) {
-        final float scale = width / graphWidth;
+        final float ratio = getRatio();
-        float sx = -touchHandler.velocityTracker.getXVelocity();
+
-        float sy = touchHandler.velocityTracker.getYVelocity();
+        float sx = -touchHandler.getXVelocity();
+        float sy = touchHandler.getYVelocity();
+
         final float asx = Math.abs(sx);
         final float asy = Math.abs(sy);
         if (asx < asy / 3) {
@@ -608,9 +705,7 @@ public class Graph2dViewNew extends View implements GraphView {
         } else if (asy < asx / 3) {
             sy = 0;
         }
-        scroller.fling(Math.round(x0 * scale),
+        scroller.fling(Math.round(x0 * ratio), Math.round(y0 * ratio), Math.round(sx), Math.round(sy), Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MIN_VALUE, Integer.MAX_VALUE);
-                Math.round(y0 * scale),
-                Math.round(sx), Math.round(sy), -10000, 10000, -10000, 10000);
         invalidate();
     }
 
@@ -631,8 +726,14 @@ public class Graph2dViewNew extends View implements GraphView {
         // Calculator.log("zoom redraw");
     }
 
+    private void invalidateGraphs() {
+        clearAllGraphs();
+        lastYMin = lastYMax = 0;
+        invalidate();
+    }
+
     private void scroll(float deltaX, float deltaY) {
-        final float scale = graphWidth / width;
+        final float scale = graphWidth / widthPxs;
         float dx = deltaX * scale;
         float dy = deltaY * scale;
         final float adx = Math.abs(dx);

android-app/src/main/java/org/solovyev/android/calculator/plot/CalculatorPlotFragment.java

@@ -19,7 +19,7 @@ import java.util.List;
  * Date: 12/30/12
  * Time: 4:43 PM
  */
-public class CalculatorArityPlotFragment extends AbstractCalculatorPlotFragment {
+public class CalculatorPlotFragment extends AbstractCalculatorPlotFragment {
 
     @Nullable
     private GraphView graphView;
@@ -28,8 +28,7 @@ public class CalculatorArityPlotFragment extends AbstractCalculatorPlotFragment
     @Override
     protected PlotBoundaries getPlotBoundaries() {
         if ( graphView != null ) {
-            // todo serso: return plot boundaries
+            return PlotBoundaries.newInstance(graphView.getXMin(), graphView.getXMax(), graphView.getYMin(), graphView.getYMax());
-            return null;
         } else {
             return null;
         }
@@ -70,7 +69,7 @@ public class CalculatorArityPlotFragment extends AbstractCalculatorPlotFragment
         if ( plotData.isPlot3d() ) {
             graphView = new Graph3dView(getActivity());
         } else {
-            graphView = new Graph2dView(getActivity());
+            graphView = new CalculatorGraph2dView(getActivity());
         }
 
         graphView.init(FunctionViewDef.newInstance(Color.WHITE, Color.WHITE, Color.DKGRAY, getBgColor()));

android-app/src/main/java/org/solovyev/android/calculator/plot/Graph2dView.java

@@ -1,618 +0,0 @@
-// Copyright (C) 2009-2010 Mihai Preda
-
-package org.solovyev.android.calculator.plot;
-
-
-import android.content.Context;
-import android.graphics.Bitmap;
-import android.graphics.Canvas;
-import android.graphics.DashPathEffect;
-import android.graphics.Matrix;
-import android.graphics.Paint;
-import android.graphics.Path;
-import android.util.AttributeSet;
-import android.view.MotionEvent;
-import android.view.View;
-import android.widget.Scroller;
-import android.widget.ZoomButtonsController;
-import org.javia.arity.Function;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-public class Graph2dView extends View implements GraphView {
-
-    private int width, height;
-    private Matrix matrix = new Matrix();
-    private Paint paint = new Paint(), textPaint = new Paint(), fillPaint = new Paint();
-
-    @NotNull
-    private GraphViewHelper graphViewHelper = GraphViewHelper.newDefaultInstance();
-
-    private final GraphData next = GraphData.newEmptyInstance();
-
-    private final GraphData endGraph = GraphData.newEmptyInstance();
-
-    @NotNull
-    private List<GraphData> graphs = new ArrayList<GraphData>(graphViewHelper.getFunctionPlotDefs().size());
-
-    private float gwidth = 8;
-    private float currentX, currentY;
-    private float lastMinX;
-    private Scroller scroller;
-    private float boundMinY, boundMaxY;
-    protected ZoomButtonsController zoomController = new ZoomButtonsController(this);
-    private ZoomTracker zoomTracker = new ZoomTracker();
-    private TouchHandler touchHandler;
-    private float lastTouchX, lastTouchY;
-
-    private static final int
-            COL_ZOOM = 0x40ffffff,
-            COL_ZOOM_TEXT1 = 0xd0ffffff,
-            COL_ZOOM_TEXT2 = 0x30ffffff;
-
-    public Graph2dView(Context context, AttributeSet attrs) {
-        super(context, attrs);
-        init(context);
-    }
-
-    public Graph2dView(Context context) {
-        super(context);
-        touchHandler = new TouchHandler(this);
-        init(context);
-    }
-
-    private void init(Context context) {
-        zoomController.setOnZoomListener(this);
-        scroller = new Scroller(context);
-        paint.setAntiAlias(false);
-        textPaint.setAntiAlias(true);
-    }
-
-	@NotNull
-    public Bitmap captureScreenshot() {
-        final Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
-        Canvas canvas = new Canvas(result);
-        onDraw(canvas);
-        return result;
-    }
-
-	@Override
-	public void setXRange(float xMin, float xMax) {
-		this.gwidth = xMax - xMin;
-		this.currentX = xMax - this.gwidth / 2;
-
-	}
-
-	private void clearAllGraphs() {
-        for (GraphData graph : graphs) {
-           graph.clear();
-        }
-
-        while ( graphViewHelper.getFunctionPlotDefs().size() > graphs.size() ) {
-            graphs.add(GraphData.newEmptyInstance());
-        }
-    }
-
-    @Override
-    public void init(@NotNull FunctionViewDef functionViewDef) {
-        this.graphViewHelper = GraphViewHelper.newInstance(functionViewDef, Collections.<ArityPlotFunction>emptyList());
-    }
-
-    public void setFunctionPlotDefs(@NotNull List<ArityPlotFunction> functionPlotDefs) {
-
-        for (ArityPlotFunction functionPlotDef: functionPlotDefs) {
-            final int arity = functionPlotDef.getFunction().arity();
-            if (arity != 0 && arity != 1) {
-                throw new IllegalArgumentException("Function must have arity 0 or 1 for 2d plot!");
-            }
-        }
-
-        this.graphViewHelper = this.graphViewHelper.copy(functionPlotDefs);
-        clearAllGraphs();
-        invalidate();
-    }
-
-    public void onVisibilityChanged(boolean visible) {
-    }
-
-    public void onZoom(boolean zoomIn) {
-        if (zoomIn) {
-            if (canZoomIn()) {
-                gwidth /= 2;
-                invalidateGraphs();
-            }
-        } else {
-            if (canZoomOut()) {
-                gwidth *= 2;
-                invalidateGraphs();
-            }
-        }
-        zoomController.setZoomInEnabled(canZoomIn());
-        zoomController.setZoomOutEnabled(canZoomOut());
-    }
-
-    public void onResume() {
-    }
-
-    public void onPause() {
-    }
-
-    public void onDetachedFromWindow() {
-        zoomController.setVisible(false);
-        super.onDetachedFromWindow();
-    }
-
-    protected void onSizeChanged(int w, int h, int ow, int oh) {
-        width = w;
-        height = h;
-        clearAllGraphs();
-        // points = new float[w+w];
-    }
-
-    protected void onDraw(Canvas canvas) {
-        if (graphViewHelper.getFunctionPlotDefs().size() == 0) {
-            return;
-        }
-        if (scroller.computeScrollOffset()) {
-            final float scale = gwidth / width;
-            currentX = scroller.getCurrX() * scale;
-            currentY = scroller.getCurrY() * scale;
-            if (!scroller.isFinished()) {
-                invalidate();
-            }
-        }
-        drawGraph(canvas);
-    }
-
-    private float eval(Function f, float x) {
-        float v = (float) f.eval(x);
-        // Calculator.log("eval " + x + "; " + v); 
-        if (v < -10000f) {
-            return -10000f;
-        }
-        if (v > 10000f) {
-            return 10000f;
-        }
-        return v;
-    }
-
-    // distance from (x,y) to the line (x1,y1) to (x2,y2), squared, multiplied by 4
-    /*
-    private float distance(float x1, float y1, float x2, float y2, float x, float y) {
-        float dx = x2 - x1;
-        float dy = y2 - y1;
-        float mx = x - x1;
-        float my = y - y1;
-        float up = dx*my - dy*mx;
-        return up*up*4/(dx*dx + dy*dy);
-    }
-    */
-
-    // distance as above when x==(x1+x2)/2. 
-    private float distance2(float x1, float y1, float x2, float y2, float y) {
-        final float dx = x2 - x1;
-        final float dy = y2 - y1;
-        final float up = dx * (y1 + y2 - y - y);
-        return up * up / (dx * dx + dy * dy);
-    }
-
-    private void computeGraph(@NotNull Function function,
-                              float minX,
-                              float maxX,
-                              float minY,
-                              float maxY,
-                              @NotNull GraphData graph) {
-        if (function.arity() == 0) {
-            float v = (float) function.eval();
-            if (v < -10000f) {
-                v = -10000f;
-            }
-            if (v > 10000f) {
-                v = 10000f;
-            }
-            graph.clear();
-            graph.push(minX, v);
-            graph.push(maxX, v);
-            return;
-        }
-
-        final float scale = width / gwidth;
-        final float maxStep = 15.8976f / scale;
-        final float minStep = .05f / scale;
-        float ythresh = 1 / scale;
-        ythresh = ythresh * ythresh;
-        // next.clear();
-        // endGraph.clear();
-        if (!graph.empty()) {
-            // Calculator.log("last " + lastMinX + " min " + minX);
-            if (minX >= lastMinX) {
-                graph.eraseBefore(minX);
-            } else {
-                graph.eraseAfter(maxX);
-                maxX = Math.min(maxX, graph.firstX());
-                graph.swap(endGraph);
-            }
-        }
-        if (graph.empty()) {
-            graph.push(minX, eval(function, minX));
-        }
-        float leftX, leftY;
-        float rightX = graph.topX(), rightY = graph.topY();
-        int nEval = 1;
-        while (true) {
-            leftX = rightX;
-            leftY = rightY;
-            if (leftX > maxX) {
-                break;
-            }
-            if (next.empty()) {
-                float x = leftX + maxStep;
-                next.push(x, eval(function, x));
-                ++nEval;
-            }
-            rightX = next.topX();
-            rightY = next.topY();
-            next.pop();
-
-            if (leftY != leftY && rightY != rightY) { // NaN
-                continue;
-            }
-
-            float dx = rightX - leftX;
-            float middleX = (leftX + rightX) / 2;
-            float middleY = eval(function, middleX);
-            ++nEval;
-            boolean middleIsOutside = (middleY < leftY && middleY < rightY) || (leftY < middleY && rightY < middleY);
-            if (dx < minStep) {
-                // Calculator.log("minStep");
-                if (middleIsOutside) {
-                    graph.push(rightX, Float.NaN);
-                }
-                graph.push(rightX, rightY);
-                continue;
-            }
-            if (middleIsOutside && ((leftY < minY && rightY > maxY) || (leftY > maxY && rightY < minY))) {
-                graph.push(rightX, Float.NaN);
-                graph.push(rightX, rightY);
-                // Calculator.log("+-inf");
-                continue;
-            }
-
-            if (!middleIsOutside) {
-                /*
-                float diff = leftY + rightY - middleY - middleY;
-                float dy = rightY - leftY;
-                float dx2 = dx*dx;
-                float distance = dx2*diff*diff/(dx2+dy*dy);
-                */
-                // Calculator.log("" + dx + ' ' + leftY + ' ' + middleY + ' ' + rightY + ' ' + distance + ' ' + ythresh);
-                if (distance2(leftX, leftY, rightX, rightY, middleY) < ythresh) {
-                    graph.push(rightX, rightY);
-                    continue;
-                }
-            }
-            next.push(rightX, rightY);
-            next.push(middleX, middleY);
-            rightX = leftX;
-            rightY = leftY;
-        }
-        if (!endGraph.empty()) {
-            graph.append(endGraph);
-        }
-        long t2 = System.currentTimeMillis();
-        // Calculator.log("graph points " + graph.size + " evals " + nEval + " time " + (t2-t1));
-
-        next.clear();
-        endGraph.clear();
-    }
-
-    private static void graphToPath(@NotNull GraphData graph, @NotNull Path path) {
-
-        final int size = graph.getSize();
-        final float[] xs = graph.getXs();
-        final float[] ys = graph.getYs();
-
-        path.rewind();
-
-        boolean newCurve = true;
-
-        for (int i = 0; i < size; i++) {
-
-            final float y = ys[i];
-            final float x = xs[i];
-
-            if (y != y) {
-                newCurve = true;
-            } else { // !NaN
-                if (newCurve) {
-                    path.moveTo(x, y);
-                    newCurve = false;
-                } else {
-                    path.lineTo(x, y);
-                }
-            }
-        }
-    }
-
-    private static final float NTICKS = 15;
-
-    private static float stepFactor(float w) {
-        float f = 1;
-        while (w / f > NTICKS) {
-            f *= 10;
-        }
-        while (w / f < NTICKS / 10) {
-            f /= 10;
-        }
-        float r = w / f;
-        if (r < NTICKS / 5) {
-            return f / 5;
-        } else if (r < NTICKS / 2) {
-            return f / 2;
-        } else {
-            return f;
-        }
-    }
-
-    private static StringBuilder b = new StringBuilder();
-    private static char[] buf = new char[20];
-
-    private static StringBuilder format(final float value) {
-        int pos = 0;
-        boolean addDot = false;
-
-        final boolean negative = value < 0;
-
-        int absValue = Math.round(Math.abs(value) * 100);
-        for (int i = 0; i < 2; ++i) {
-            int digit = absValue % 10;
-            absValue /= 10;
-            if (digit != 0 || addDot) {
-                buf[pos++] = (char) ('0' + digit);
-                addDot = true;
-            }
-        }
-        if (addDot) {
-            buf[pos++] = '.';
-        }
-        if (absValue == 0) {
-            buf[pos++] = '0';
-        }
-        while (absValue != 0) {
-            buf[pos++] = (char) ('0' + (absValue % 10));
-            absValue /= 10;
-        }
-        if (negative) {
-            buf[pos++] = '-';
-        }
-        b.setLength(0);
-        b.append(buf, 0, pos);
-        b.reverse();
-        return b;
-    }
-
-    private void drawGraph(Canvas canvas) {
-        long t1 = System.currentTimeMillis();
-        float minX = getXMin();
-        float maxX = getXMax(minX);
-        float ywidth = gwidth * height / width;
-        float minY = currentY - ywidth / 2;
-        float maxY = minY + ywidth;
-        if (minY < boundMinY || maxY > boundMaxY) {
-            float halfw = ywidth / 2;
-            boundMinY = minY - halfw;
-            boundMaxY = maxY + halfw;
-            clearAllGraphs();
-        }
-
-        canvas.drawColor(graphViewHelper.getFunctionViewDef().getBackgroundColor());
-
-        paint.setStrokeWidth(0);
-        paint.setAntiAlias(false);
-        paint.setStyle(Paint.Style.STROKE);
-
-        final float h2 = height / 2f;
-        final float scale = width / gwidth;
-
-        float x0 = -minX * scale;
-        boolean drawYAxis = true;
-        if (x0 < 25) {
-            x0 = 25;
-            // drawYAxis = false;
-        } else if (x0 > width - 3) {
-            x0 = width - 3;
-            // drawYAxis = false;
-        }
-        float y0 = maxY * scale;
-        if (y0 < 3) {
-            y0 = 3;
-        } else if (y0 > height - 15) {
-            y0 = height - 15;
-        }
-
-        final float tickSize = 3;
-        final float y2 = y0 + tickSize;
-
-
-        {
-            // GRID
-
-            paint.setPathEffect(new DashPathEffect(new float[]{5, 10}, 0));
-            paint.setColor(graphViewHelper.getFunctionViewDef().getGridColor());
-
-            float step = stepFactor(gwidth);
-            // Calculator.log("width " + gwidth + " step " + step);
-            float v = ((int) (minX / step)) * step;
-            textPaint.setColor(graphViewHelper.getFunctionViewDef().getAxisLabelsColor());
-            textPaint.setTextSize(12);
-            textPaint.setTextAlign(Paint.Align.CENTER);
-            float stepScale = step * scale;
-            for (float x = (v - minX) * scale; x <= width; x += stepScale, v += step) {
-                canvas.drawLine(x, 0, x, height, paint);
-                if (!(-.001f < v && v < .001f)) {
-                    StringBuilder b = format(v);
-                    canvas.drawText(b, 0, b.length(), x, y2 + 10, textPaint);
-                }
-            }
-
-            final float x1 = x0 - tickSize;
-            v = ((int) (minY / step)) * step;
-            textPaint.setTextAlign(Paint.Align.RIGHT);
-            for (float y = height - (v - minY) * scale; y >= 0; y -= stepScale, v += step) {
-                canvas.drawLine(0, y, width, y, paint);
-                if (!(-.001f < v && v < .001f)) {
-                    StringBuilder b = format(v);
-                    canvas.drawText(b, 0, b.length(), x1, y + 4, textPaint);
-                }
-            }
-
-            paint.setPathEffect(null);
-        }
-
-        {
-            // AXIS
-
-            paint.setColor(graphViewHelper.getFunctionViewDef().getAxisColor());
-            if (drawYAxis) {
-                canvas.drawLine(x0, 0, x0, height, paint);
-            }
-            canvas.drawLine(0, y0, width, y0, paint);
-        }
-
-
-        matrix.reset();
-        matrix.preTranslate(-currentX, -currentY);
-        matrix.postScale(scale, -scale);
-        matrix.postTranslate(width / 2, height / 2);
-
-        paint.setAntiAlias(false);
-
-        {
-            //GRAPH
-
-            final List<ArityPlotFunction> functionPlotDefs = graphViewHelper.getFunctionPlotDefs();
-
-            // create path once
-            final Path path = new Path();
-
-            for (int i = 0; i < functionPlotDefs.size(); i++) {
-                final ArityPlotFunction fpd = functionPlotDefs.get(i);
-                computeGraph(fpd.getFunction(), minX, maxX, boundMinY, boundMaxY, graphs.get(i));
-
-                graphToPath(graphs.get(i), path);
-
-                path.transform(matrix);
-
-                AbstractCalculatorPlotFragment.applyToPaint(fpd.getLineDef(), paint);
-
-                canvas.drawPath(path, paint);
-            }
-        }
-
-
-        lastMinX = minX;
-    }
-
-    private float getXMax(float minX) {
-        return minX + gwidth;
-    }
-
-    private float getXMax() {
-        return getXMax(getXMin());
-    }
-
-    private float getXMin() {
-        return currentX - gwidth / 2;
-    }
-
-    private boolean canZoomIn() {
-        return true;
-    }
-
-    private boolean canZoomOut() {
-        return true;
-    }
-
-    private void invalidateGraphs() {
-        clearAllGraphs();
-        boundMinY = boundMaxY = 0;
-        invalidate();
-    }
-
-    @Override
-    public boolean onTouchEvent(MotionEvent event) {
-        return touchHandler != null ? touchHandler.onTouchEvent(event) : super.onTouchEvent(event);
-    }
-
-    public void onTouchDown(float x, float y) {
-        zoomController.setVisible(true);
-        if (!scroller.isFinished()) {
-            scroller.abortAnimation();
-        }
-        lastTouchX = x;
-        lastTouchY = y;
-    }
-
-    public void onTouchMove(float x, float y) {
-        float deltaX = x - lastTouchX;
-        float deltaY = y - lastTouchY;
-        if (deltaX < -1 || deltaX > 1 || deltaY < -1 || deltaY > 1) {
-            scroll(-deltaX, deltaY);
-            lastTouchX = x;
-            lastTouchY = y;
-            invalidate();
-        }
-    }
-
-    public void onTouchUp(float x, float y) {
-        final float scale = width / gwidth;
-        float sx = -touchHandler.velocityTracker.getXVelocity();
-        float sy = touchHandler.velocityTracker.getYVelocity();
-        final float asx = Math.abs(sx);
-        final float asy = Math.abs(sy);
-        if (asx < asy / 3) {
-            sx = 0;
-        } else if (asy < asx / 3) {
-            sy = 0;
-        }
-        scroller.fling(Math.round(currentX * scale),
-                Math.round(currentY * scale),
-                Math.round(sx), Math.round(sy), -10000, 10000, -10000, 10000);
-        invalidate();
-    }
-
-    public void onTouchZoomDown(float x1, float y1, float x2, float y2) {
-        zoomTracker.start(gwidth, x1, y1, x2, y2);
-    }
-
-    public void onTouchZoomMove(float x1, float y1, float x2, float y2) {
-        if (!zoomTracker.update(x1, y1, x2, y2)) {
-            return;
-        }
-        float targetGwidth = zoomTracker.value;
-        if (targetGwidth > .25f && targetGwidth < 200) {
-            gwidth = targetGwidth;
-        }
-        // scroll(-zoomTracker.moveX, zoomTracker.moveY);
-        invalidateGraphs();
-        // Calculator.log("zoom redraw");
-    }
-
-    private void scroll(float deltaX, float deltaY) {
-        final float scale = gwidth / width;
-        float dx = deltaX * scale;
-        float dy = deltaY * scale;
-        final float adx = Math.abs(dx);
-        final float ady = Math.abs(dy);
-        if (adx < ady / 3) {
-            dx = 0;
-        } else if (ady < adx / 3) {
-            dy = 0;
-        }
-        currentX += dx;
-        currentY += dy;
-    }
-}

android-app/src/main/java/org/solovyev/android/calculator/plot/Graph3dView.java

@@ -133,8 +133,8 @@ public class Graph3dView extends GLView implements GraphView {
     }
 
     public void onTouchUp(float x, float y) {
-        float vx = touchHandler.velocityTracker.getXVelocity();
+        float vx = touchHandler.getXVelocity();
-        float vy = touchHandler.velocityTracker.getYVelocity();
+        float vy = touchHandler.getYVelocity();
         // Calculator.log("velocity " + vx + ' ' + vy);
         setRotation(vx / 100, vy / 100);
         if (shouldRotate()) {
@@ -152,7 +152,7 @@ public class Graph3dView extends GLView implements GraphView {
 
     @Override
     public boolean onTouchEvent(MotionEvent event) {
-        return touchHandler != null ? touchHandler.onTouchEvent(event) : super.onTouchEvent(event);
+        return touchHandler != null ? touchHandler.handleTouchEvent(event) : super.onTouchEvent(event);
     }
 
     // ----
@@ -195,6 +195,26 @@ public class Graph3dView extends GLView implements GraphView {
 		//To change body of implemented methods use File | Settings | File Templates.
 	}
 
+    @Override
+    public float getXMin() {
+        return 0;  //To change body of implemented methods use File | Settings | File Templates.
+    }
+
+    @Override
+    public float getXMax() {
+        return 0;  //To change body of implemented methods use File | Settings | File Templates.
+    }
+
+    @Override
+    public float getYMin() {
+        return 0;  //To change body of implemented methods use File | Settings | File Templates.
+    }
+
+    @Override
+    public float getYMax() {
+        return 0;  //To change body of implemented methods use File | Settings | File Templates.
+    }
+
     @Override
     public void onSurfaceCreated(GL10 gl, int width, int height) {
         gl.glDisable(GL10.GL_DITHER);

android-app/src/main/java/org/solovyev/android/calculator/plot/GraphView.java

@@ -8,9 +8,7 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
 
-public interface GraphView extends ZoomButtonsController.OnZoomListener, TouchHandler.TouchHandlerInterface {
+public interface GraphView extends ZoomButtonsController.OnZoomListener, TouchHandler.TouchHandlerListener {
-
-    static final String SCREENSHOT_DIR = "/screenshots";
 
     public void init(@NotNull FunctionViewDef functionViewDef);
 
@@ -24,6 +22,14 @@ public interface GraphView extends ZoomButtonsController.OnZoomListener, TouchHa
 
 	void setXRange(float xMin, float xMax);
 
+    float getXMin();
+
+    float getXMax();
+
+    float getYMin();
+
+    float getYMax();
+
 /*	void increaseDensity();
 	void decreaseDensity();*/
 

android-app/src/main/java/org/solovyev/android/calculator/plot/MotionEventWrap.java

@@ -1,22 +0,0 @@
-// Copyright (C) 2010 Mihai Preda
-
-package org.solovyev.android.calculator.plot;
-
-import android.os.Build;
-import android.view.MotionEvent;
-
-class MotionEventWrap {
-    private static final boolean IS_API_5 = Build.VERSION.SDK_INT >= 5;
-
-    static int getPointerCount(MotionEvent event) {
-        return IS_API_5 ? MotionEventWrapNew.getPointerCount(event) : 1;
-    }
-
-    static float getX(MotionEvent event, int idx) {
-        return IS_API_5 ? MotionEventWrapNew.getX(event, idx) : 0;
-    }
-
-    static float getY(MotionEvent event, int idx) {
-        return IS_API_5 ? MotionEventWrapNew.getX(event, idx) : 0;
-    }
-}

android-app/src/main/java/org/solovyev/android/calculator/plot/MotionEventWrapNew.java

@@ -1,19 +0,0 @@
-// Copyright (C) 2010 Mihai Preda
-
-package org.solovyev.android.calculator.plot;
-
-import android.view.MotionEvent;
-
-class MotionEventWrapNew {
-    static int getPointerCount(MotionEvent event) {
-        return event.getPointerCount();
-    }
-    
-    static float getX(MotionEvent event, int idx) {
-        return event.getX(idx);
-    }
-    
-    static float getY(MotionEvent event, int idx) {
-        return event.getY(idx);
-    }
-}

android-app/src/main/java/org/solovyev/android/calculator/plot/TouchHandler.java

@@ -4,54 +4,66 @@ package org.solovyev.android.calculator.plot;
 
 import android.view.MotionEvent;
 import android.view.VelocityTracker;
+import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.AndroidUtils2;
 
 class TouchHandler {
-    static interface TouchHandlerInterface {
+
+    static interface TouchHandlerListener {
         void onTouchDown(float x, float y);
+
         void onTouchMove(float x, float y);
+
         void onTouchUp(float x, float y);
+
         void onTouchZoomDown(float x1, float y1, float x2, float y2);
+
         void onTouchZoomMove(float x1, float y1, float x2, float y2);
     }
 
-    VelocityTracker velocityTracker = VelocityTracker.obtain();
+    @NotNull
+    private final VelocityTracker velocityTracker = VelocityTracker.obtain();
 
-    private boolean isAfterZoom;
+    private boolean afterZoom;
-    private TouchHandlerInterface listener;
 
-    TouchHandler(TouchHandlerInterface listener) {
+    @NotNull
+    private TouchHandlerListener listener;
+
+    TouchHandler(@NotNull TouchHandlerListener listener) {
         this.listener = listener;
     }
 
-    public boolean onTouchEvent(MotionEvent event) {
+    public boolean handleTouchEvent(@NotNull MotionEvent event) {
         // Calculator.log("touch " + event + ' ' + event.getPointerCount() + event.getPointerId(0));
 
-        int fullAction = event.getAction();
+        final int fullAction = event.getAction();
-        int action  = fullAction & MotionEvent.ACTION_MASK;
+        final int action = fullAction & MotionEvent.ACTION_MASK;
-        int pointer = (fullAction & MotionEvent.ACTION_POINTER_ID_MASK) >> MotionEvent.ACTION_POINTER_ID_SHIFT;
+        final int pointer = (fullAction & MotionEvent.ACTION_POINTER_ID_MASK) >> MotionEvent.ACTION_POINTER_ID_SHIFT;
+
         float x = event.getX();
         float y = event.getY();
-        int nPoints = MotionEventWrap.getPointerCount(event);
+
+        int pointerCount = AndroidUtils2.getPointerCountFromMotionEvent(event);
 
         switch (action) {
             case MotionEvent.ACTION_DOWN:
-            isAfterZoom = false;
+                afterZoom = false;
                 velocityTracker.clear();
                 velocityTracker.addMovement(event);
                 listener.onTouchDown(x, y);
                 break;
 
             case MotionEvent.ACTION_MOVE:
-            if (nPoints == 1) {
+                if (pointerCount == 1) {
-                if (isAfterZoom) {
+                    if (afterZoom) {
                         velocityTracker.clear();
                         listener.onTouchDown(x, y);
-                    isAfterZoom = false;
+                        afterZoom = false;
                     }
                     velocityTracker.addMovement(event);
                     listener.onTouchMove(x, y);
-            } else if (nPoints == 2) {
+                } else if (pointerCount == 2) {
-                listener.onTouchZoomMove(x, y, MotionEventWrap.getX(event, 1), MotionEventWrap.getY(event, 1));
+                    listener.onTouchZoomMove(x, y, AndroidUtils2.getXFromMotionEvent(event, 1), AndroidUtils2.getYFromMotionEvent(event, 1));
                 }
                 break;
 
@@ -62,18 +74,25 @@ class TouchHandler {
                 break;
 
             case MotionEvent.ACTION_POINTER_DOWN:
-            if (nPoints == 2) {
+                if (pointerCount == 2) {
-                listener.onTouchZoomDown(x, y, MotionEventWrap.getX(event, 1), MotionEventWrap.getY(event, 1));
+                    listener.onTouchZoomDown(x, y, AndroidUtils2.getXFromMotionEvent(event, 1), AndroidUtils2.getYFromMotionEvent(event, 1));
                 }
                 break;
 
             case MotionEvent.ACTION_POINTER_UP:
-            if (nPoints == 2) {
+                if (pointerCount == 2) {
-                isAfterZoom = true;
+                    afterZoom = true;
                 }
                 break;
         }
         return true;
     }
 
+    public float getXVelocity() {
+        return velocityTracker.getXVelocity();
+    }
+
+    public float getYVelocity() {
+        return velocityTracker.getYVelocity();
+    }
 }