Calc UI on Android Viewer

Adding Calc UI. Two blank views are added as
row and column headers. CommonCanvasElement
is used to draw header cells on the views. [WIP]

Change-Id: I37eaa82805045ab650fd127e54c8421c61a4ea27
Reviewed-on: https://gerrit.libreoffice.org/38936
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
Tested-by: Tomaž Vajngerl <quikee@gmail.com>

12 files changed, 369 insertions, 19 deletions

diff --git a/android/source/res/layout/activity_main.xml b/android/source/res/layout/activity_main.xml
index bfa575b57f36..fb5ba1ef7d32 100644
--- a/android/source/res/layout/activity_main.xml
+++ b/android/source/res/layout/activity_main.xml
@@ -36,22 +36,53 @@
             </android.support.design.widget.AppBarLayout>
 
             <RelativeLayout
-                android:id="@+id/gecko_layout"
                 android:layout_width="match_parent"
-                android:layout_height="match_parent"
-                android:orientation="vertical">
+                android:layout_height="match_parent">
 
-                <org.mozilla.gecko.gfx.LayerView
-                    android:id="@+id/layer_view"
+                <View
+                    android:id="@+id/calc_header_top_left"
+                    android:layout_width="@dimen/calc_header_width"
+                    android:layout_height="@dimen/calc_header_height"
+                    android:visibility="gone"/>
+
+                <org.libreoffice.overlay.CalcHeadersView
+                    android:id="@+id/calc_header_column"
+                    android:layout_width="match_parent"
+                    android:layout_height="@dimen/calc_header_height"
+                    android:layout_toRightOf="@+id/calc_header_top_left"
+                    android:layout_toEndOf="@+id/calc_header_top_left"
+                    android:visibility="gone"/>
+
+                <org.libreoffice.overlay.CalcHeadersView
+                    android:id="@+id/calc_header_row"
+                    android:layout_width="@dimen/calc_header_width"
+                    android:layout_height="match_parent"
+                    android:layout_below="@+id/calc_header_top_left"
+                    android:visibility="gone"/>
+
+                <RelativeLayout
+                    android:id="@+id/gecko_layout"
                     android:layout_width="match_parent"
-                    android:layout_height="match_parent"/>
+                    android:layout_height="match_parent"
+                    android:orientation="vertical"
+                    android:layout_toRightOf="@+id/calc_header_row"
+                    android:layout_toEndOf="@+id/calc_header_row"
+                    android:layout_below="@+id/calc_header_column">
+
+                    <org.mozilla.gecko.gfx.LayerView
+                        android:id="@+id/layer_view"
+                        android:layout_width="match_parent"
+                        android:layout_height="match_parent"/>
 
-                <org.libreoffice.overlay.DocumentOverlayView
-                    android:id="@+id/text_cursor_view"
-                    android:layout_width="fill_parent"
-                    android:layout_height="fill_parent"/>
+                    <org.libreoffice.overlay.DocumentOverlayView
+                        android:id="@+id/text_cursor_view"
+                        android:layout_width="fill_parent"
+                        android:layout_height="fill_parent"/>
+
+                </RelativeLayout>
 
             </RelativeLayout>
+
         </LinearLayout>
 
         <include layout="@layout/toolbar_bottom"/>
diff --git a/android/source/res/values/dimens.xml b/android/source/res/values/dimens.xml
index 3de476c0cc42..8a153790ac69 100644
--- a/android/source/res/values/dimens.xml
+++ b/android/source/res/values/dimens.xml
@@ -9,4 +9,6 @@
     <dimen name="list_item_margin">8dp</dimen>
     <dimen name="file_icon_width">32dp</dimen>
     <dimen name="toolbar_height">256dp</dimen>
+    <dimen name="calc_header_width">48dp</dimen>
+    <dimen name="calc_header_height">24dp</dimen>
 </resources>
diff --git a/android/source/src/java/org/libreoffice/LOEvent.java b/android/source/src/java/org/libreoffice/LOEvent.java
index 14980dca0ec4..7846f7331bbd 100644
--- a/android/source/src/java/org/libreoffice/LOEvent.java
+++ b/android/source/src/java/org/libreoffice/LOEvent.java
@@ -38,6 +38,7 @@ public class LOEvent implements Comparable<LOEvent> {
     public static final int SAVE_AS = 17;
     public static final int UPDATE_PART_PAGE_RECT = 18;
     public static final int UPDATE_ZOOM_CONSTRAINTS = 19;
+    public static final int UPDATE_CALC_HEADERS = 20;
 
     public final int mType;
     public int mPriority = 0;
diff --git a/android/source/src/java/org/libreoffice/LOKitThread.java b/android/source/src/java/org/libreoffice/LOKitThread.java
index dac8cc43109c..9ab54c20a1f8 100644
--- a/android/source/src/java/org/libreoffice/LOKitThread.java
+++ b/android/source/src/java/org/libreoffice/LOKitThread.java
@@ -156,6 +156,9 @@ class LOKitThread extends Thread {
         mLayerClient.clearAndResetlayers();
         redraw();
         updatePartPageRectangles();
+        if (mTileProvider.isSpreadsheet()) {
+            updateCalcHeaders();
+        }
     }
 
     /**
@@ -170,11 +173,15 @@ class LOKitThread extends Thread {
 
     private void updateZoomConstraints() {
         mLayerClient = mContext.getLayerClient();
-
-        // Set min zoom to the page width so that you cannot zoom below page width
-        // applies to all types of document; in the future spreadsheets may be singled out
-        float minZoom = mLayerClient.getViewportMetrics().getWidth()/mTileProvider.getPageWidth();
-        mLayerClient.setZoomConstraints(new ZoomConstraints(true, 0.0f, minZoom, 0.0f));
+        if (mTileProvider.isSpreadsheet()) {
+            // Calc has a fixed zoom at 1x and doesn't allow zooming for now
+            mLayerClient.setZoomConstraints(new ZoomConstraints(false, 1f, 0f, 0f));
+        } else {
+            // Set min zoom to the page width so that you cannot zoom below page width
+            // applies to all types of document; in the future spreadsheets may be singled out
+            float minZoom = mLayerClient.getViewportMetrics().getWidth()/mTileProvider.getPageWidth();
+            mLayerClient.setZoomConstraints(new ZoomConstraints(true, 1f, minZoom, 0f));
+        }
     }
 
 
@@ -343,9 +350,19 @@ class LOKitThread extends Thread {
             case LOEvent.UPDATE_ZOOM_CONSTRAINTS:
                 updateZoomConstraints();
                 break;
+            case LOEvent.UPDATE_CALC_HEADERS:
+                updateCalcHeaders();
+                break;
+
         }
     }
 
+    private void updateCalcHeaders() {
+        LOKitTileProvider tileProvider = (LOKitTileProvider)mTileProvider;
+        String values = tileProvider.getCalcHeaders();
+        mContext.getCalcHeadersController().setHeaders(values);
+    }
+
     /**
      * Request a change of the handle position.
      */
diff --git a/android/source/src/java/org/libreoffice/LOKitTileProvider.java b/android/source/src/java/org/libreoffice/LOKitTileProvider.java
index 6fb8a9b80671..3278265dfa3f 100644
--- a/android/source/src/java/org/libreoffice/LOKitTileProvider.java
+++ b/android/source/src/java/org/libreoffice/LOKitTileProvider.java
@@ -28,6 +28,7 @@ import java.nio.ByteBuffer;
  */
 class LOKitTileProvider implements TileProvider {
     private static final String LOGTAG = LOKitTileProvider.class.getSimpleName();
+    private static final float DPI_1X_ZOOM = 96f; // for use in Calc at fixed zoom 1x
     private static int TILE_SIZE = 256;
     private final float mTileWidth;
     private final float mTileHeight;
@@ -53,9 +54,6 @@ class LOKitTileProvider implements TileProvider {
     LOKitTileProvider(LibreOfficeMainActivity context, Document.MessageCallback messageCallback, String input) {
         mContext = context;
         mMessageCallback = messageCallback;
-        mDPI = LOKitShell.getDpi(mContext);
-        mTileWidth = pixelToTwip(TILE_SIZE, mDPI);
-        mTileHeight = pixelToTwip(TILE_SIZE, mDPI);
 
         LibreOfficeKit.putenv("SAL_LOG=+WARN+INFO");
         LibreOfficeKit.init(mContext);
@@ -80,6 +78,15 @@ class LOKitTileProvider implements TileProvider {
 
         Log.i(LOGTAG, "====> mDocument = " + mDocument);
 
+        if(isSpreadsheet()) {
+            mDPI = DPI_1X_ZOOM; // Calc has a fixed zoom at 1x
+        } else {
+            mDPI = LOKitShell.getDpi(mContext);
+        }
+
+        mTileWidth = pixelToTwip(TILE_SIZE, mDPI);
+        mTileHeight = pixelToTwip(TILE_SIZE, mDPI);
+
         if (mDocument != null)
             mDocument.initializeForRendering();
 
@@ -124,6 +131,11 @@ class LOKitTileProvider implements TileProvider {
             mContext.getToolbarController().disableMenuItem(R.id.action_parts, true);
         }
 
+        // Enable headers for Calc documents
+        if (mDocument.getDocumentType() == Document.DOCTYPE_SPREADSHEET) {
+            mContext.initializeCalcHeaders();
+        }
+
         mDocument.setPart(0);
 
         setupDocumentFonts();
@@ -230,6 +242,18 @@ class LOKitTileProvider implements TileProvider {
     }
 
     /**
+     * Fetch Calc header information.
+     */
+    public String getCalcHeaders() {
+        long nX = 0;
+        long nY = 0;
+        long nWidth = mDocument.getDocumentWidth();
+        long nHeight = mDocument.getDocumentHeight();
+        return mDocument.getCommandValues(".uno:ViewRowColumnHeaders?x=" + nX + "&y=" + nY
+                + "&width=" + nWidth + "&height=" + nHeight);
+    }
+
+    /**
      * @see TileProvider#onSwipeLeft()
      */
     @Override
diff --git a/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java b/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java
index 8aeb1f5ff816..95c90de9b69a 100755
--- a/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java
+++ b/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java
@@ -33,6 +33,7 @@ import android.widget.ListView;
 import android.widget.TabHost;
 import android.widget.Toast;
 
+import org.libreoffice.overlay.CalcHeadersController;
 import org.libreoffice.overlay.DocumentOverlay;
 import org.libreoffice.storage.DocumentProviderFactory;
 import org.libreoffice.storage.IFile;
@@ -91,6 +92,7 @@ public class LibreOfficeMainActivity extends AppCompatActivity implements Settin
     private ToolbarController mToolbarController;
     private FontController mFontController;
     private SearchController mSearchController;
+    private CalcHeadersController mCalcHeadersController;
 
     public GeckoLayerClient getLayerClient() {
         return mLayerClient;
@@ -645,6 +647,10 @@ public class LibreOfficeMainActivity extends AppCompatActivity implements Settin
         return mDocumentOverlay;
     }
 
+    public CalcHeadersController getCalcHeadersController() {
+        return mCalcHeadersController;
+    }
+
     public ToolbarController getToolbarController() {
         return mToolbarController;
     }
@@ -685,6 +691,18 @@ public class LibreOfficeMainActivity extends AppCompatActivity implements Settin
         }
     }
 
+    public void initializeCalcHeaders() {
+        mCalcHeadersController = new CalcHeadersController(this, mLayerClient.getView());
+        LOKitShell.getMainHandler().post(new Runnable() {
+            @Override
+            public void run() {
+                findViewById(R.id.calc_header_top_left).setVisibility(View.VISIBLE);
+                findViewById(R.id.calc_header_row).setVisibility(View.VISIBLE);
+                findViewById(R.id.calc_header_column).setVisibility(View.VISIBLE);
+            }
+        });
+    }
+
     private class DocumentPartClickListener implements android.widget.AdapterView.OnItemClickListener {
         @Override
         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
diff --git a/android/source/src/java/org/libreoffice/canvas/CalcHeaderCell.java b/android/source/src/java/org/libreoffice/canvas/CalcHeaderCell.java
new file mode 100644
index 000000000000..dc46f047c10c
--- /dev/null
+++ b/android/source/src/java/org/libreoffice/canvas/CalcHeaderCell.java
@@ -0,0 +1,48 @@
+package org.libreoffice.canvas;
+
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
+import android.graphics.RectF;
+import android.text.TextPaint;
+
+public class CalcHeaderCell extends CommonCanvasElement {
+    private TextPaint mTextPaint = new TextPaint();
+    private Paint mBgPaint = new Paint();
+    private RectF mBounds;
+    private String mText;
+
+    public CalcHeaderCell(float left, float top, float width, float height, String text) {
+        mBounds = new RectF(left, top, left + width, top + height);
+        mBgPaint.setStyle(Style.STROKE);
+        mBgPaint.setColor(Color.GRAY);
+        mBgPaint.setAlpha(100);  // hard coded for now
+        mTextPaint.setColor(Color.GRAY);
+        mTextPaint.setTextSize(24f); // hard coded for now
+        mText = text;
+    }
+
+    /**
+     * Implement hit test here
+     *
+     * @param x - x coordinate of the
+     * @param y - y coordinate of the
+     */
+    @Override
+    public boolean onHitTest(float x, float y) {
+        return false;
+    }
+
+    /**
+     * Called inside draw if the element is visible. Override this method to
+     * draw the element on the canvas.
+     *
+     * @param canvas - the canvas
+     */
+    @Override
+    public void onDraw(Canvas canvas) {
+        canvas.drawRect(mBounds, mBgPaint);
+        canvas.drawText(mText, mBounds.left, mBounds.bottom, mTextPaint);
+    }
+}
\ No newline at end of file
diff --git a/android/source/src/java/org/libreoffice/overlay/CalcHeadersController.java b/android/source/src/java/org/libreoffice/overlay/CalcHeadersController.java
new file mode 100644
index 000000000000..80cb0e5791d8
--- /dev/null
+++ b/android/source/src/java/org/libreoffice/overlay/CalcHeadersController.java
@@ -0,0 +1,98 @@
+package org.libreoffice.overlay;
+
+import android.util.Log;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.libreoffice.LOEvent;
+import org.libreoffice.LOKitShell;
+import org.libreoffice.LibreOfficeMainActivity;
+import org.libreoffice.R;
+import org.mozilla.gecko.gfx.LayerView;
+
+import java.util.ArrayList;
+
+public class CalcHeadersController {
+    private static final String LOGTAG = CalcHeadersController.class.getSimpleName();
+    private static final float DPI_1X_ZOOM = 96f; // Calc uses a fixed zoom a 1x which is 96 dpi
+
+    private final CalcHeadersView mCalcRowHeadersView;
+    private final CalcHeadersView mCalcColumnHeadersView;
+
+    private LibreOfficeMainActivity mContext;
+
+    public CalcHeadersController(LibreOfficeMainActivity context, LayerView layerView) {
+        mContext = context;
+        mContext.getDocumentOverlay().setCalcHeadersController(this);
+        mCalcRowHeadersView = (CalcHeadersView) context.findViewById(R.id.calc_header_row);
+        mCalcColumnHeadersView = (CalcHeadersView) context.findViewById(R.id.calc_header_column);
+        if (mCalcColumnHeadersView == null || mCalcRowHeadersView == null) {
+            Log.e(LOGTAG, "Failed to initialize Calc headers - View is null");
+        } else {
+            mCalcRowHeadersView.initialize(layerView, true);
+            mCalcColumnHeadersView.initialize(layerView, false);
+        }
+        LOKitShell.sendEvent(new LOEvent(LOEvent.UPDATE_CALC_HEADERS));
+    }
+
+    public void setHeaders(String headers) {
+        HeaderInfo parsedHeaders = parseHeaderInfo(headers);
+        if (parsedHeaders != null) {
+            mCalcRowHeadersView.setHeaders(parsedHeaders.rowLabels, parsedHeaders.rowDimens);
+            mCalcColumnHeadersView.setHeaders(parsedHeaders.columnLabels, parsedHeaders.columnDimens);
+            showHeaders();
+        } else {
+            Log.e(LOGTAG, "Parse header info JSON failed.");
+        }
+    }
+
+    public void showHeaders() {
+        LOKitShell.getMainHandler().post(new Runnable() {
+            @Override
+            public void run() {
+                mCalcColumnHeadersView.invalidate();
+                mCalcRowHeadersView.invalidate();
+            }
+        });
+    }
+
+    private HeaderInfo parseHeaderInfo(String headers) {
+        HeaderInfo headerInfo = new HeaderInfo();
+        try {
+            JSONObject collectiveResult = new JSONObject(headers);
+            JSONArray rowResult = collectiveResult.getJSONArray("rows");
+            for (int i = 0; i < rowResult.length(); i++) {
+                headerInfo.rowLabels.add(rowResult.getJSONObject(i).getString("text"));
+                headerInfo.rowDimens.add(twipToPixel(rowResult.getJSONObject(i).getLong("size"), DPI_1X_ZOOM));
+            }
+            JSONArray columnResult = collectiveResult.getJSONArray("columns");
+            for (int i = 0; i < columnResult.length(); i++) {
+                headerInfo.columnLabels.add(columnResult.getJSONObject(i).getString("text"));
+                headerInfo.columnDimens.add(twipToPixel(columnResult.getJSONObject(i).getLong("size"), DPI_1X_ZOOM));
+            }
+            return headerInfo;
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    private float twipToPixel(float input, float dpi) {
+        return input / 1440.0f * dpi;
+    }
+
+    private class HeaderInfo {
+        ArrayList<String> rowLabels;
+        ArrayList<Float> rowDimens;
+        ArrayList<String> columnLabels;
+        ArrayList<Float> columnDimens;
+
+        private HeaderInfo() {
+            rowLabels = new ArrayList<String>();
+            rowDimens = new ArrayList<Float>();
+            columnDimens = new ArrayList<Float>();
+            columnLabels = new ArrayList<String>();
+        }
+    }
+}
diff --git a/android/source/src/java/org/libreoffice/overlay/CalcHeadersView.java b/android/source/src/java/org/libreoffice/overlay/CalcHeadersView.java
new file mode 100644
index 000000000000..d15941470bd7
--- /dev/null
+++ b/android/source/src/java/org/libreoffice/overlay/CalcHeadersView.java
@@ -0,0 +1,95 @@
+package org.libreoffice.overlay;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.PointF;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.view.View;
+
+import org.libreoffice.canvas.CalcHeaderCell;
+import org.mozilla.gecko.gfx.ImmutableViewportMetrics;
+import org.mozilla.gecko.gfx.LayerView;
+
+import java.util.ArrayList;
+
+public class CalcHeadersView extends View implements View.OnTouchListener {
+
+    private boolean mInitialized;
+    private LayerView mLayerView;
+    private boolean mIsRow; // true if this is for row headers, false for column
+    private ArrayList<String> mLabels;
+    private ArrayList<Float> mDimens;
+
+    public CalcHeadersView(Context context) {
+        super(context);
+    }
+
+    public CalcHeadersView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public CalcHeadersView(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public void initialize(LayerView layerView, boolean isRow) {
+        if (!mInitialized) {
+            setOnTouchListener(this);
+            mLayerView = layerView;
+            mIsRow = isRow;
+
+            mInitialized = true;
+        }
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+        if (mInitialized && mDimens != null && mLabels != null) {
+            updateHeaders(canvas);
+        }
+    }
+
+    private void updateHeaders(Canvas canvas) {
+        ImmutableViewportMetrics metrics = mLayerView.getViewportMetrics();
+        float zoom = metrics.getZoomFactor();
+        PointF origin = metrics.getOrigin();
+        boolean inRangeOfVisibleHeaders = false; // a helper variable for skipping unnecessary onDraw()'s
+        float top,bottom,left,right;
+        for (int i = 1; i < mLabels.size(); i++) {
+            if (mIsRow) {
+                top = -origin.y + zoom*mDimens.get(i-1);
+                bottom = -origin.y + zoom*mDimens.get(i);
+                if (top <= getHeight() && bottom >= 0) {
+                    inRangeOfVisibleHeaders = true;
+                    new CalcHeaderCell(0f, top, getWidth(), bottom - top, mLabels.get(i)).onDraw(canvas);
+                } else {
+                    if (inRangeOfVisibleHeaders) {
+                        break;
+                    }
+                }
+            } else {
+                left = -origin.x + zoom*mDimens.get(i-1);
+                right = -origin.x + zoom*mDimens.get(i);
+                if (left <= getWidth() && right >= 0) {
+                    new CalcHeaderCell(left, 0f, right - left, getHeight(), mLabels.get(i)).onDraw(canvas);
+                } else {
+                    if (inRangeOfVisibleHeaders) {
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    @Override
+    public boolean onTouch(View v, MotionEvent event) {
+        return false;
+    }
+
+    public void setHeaders(ArrayList<String> labels, ArrayList<Float> dimens) {
+        mLabels = labels;
+        mDimens = dimens;
+    }
+}
diff --git a/android/source/src/java/org/libreoffice/overlay/DocumentOverlay.java b/android/source/src/java/org/libreoffice/overlay/DocumentOverlay.java
index d9d2b372b714..4809921012bc 100644
--- a/android/source/src/java/org/libreoffice/overlay/DocumentOverlay.java
+++ b/android/source/src/java/org/libreoffice/overlay/DocumentOverlay.java
@@ -8,11 +8,11 @@
  */
 package org.libreoffice.overlay;
 
-import org.libreoffice.LibreOfficeMainActivity;
 import android.graphics.RectF;
 import android.util.Log;
 
 import org.libreoffice.LOKitShell;
+import org.libreoffice.LibreOfficeMainActivity;
 import org.libreoffice.R;
 import org.libreoffice.canvas.SelectionHandle;
 import org.mozilla.gecko.gfx.Layer;
@@ -237,6 +237,11 @@ public class DocumentOverlay {
     public RectF getCurrentCursorPosition() {
         return mDocumentOverlayView.getCurrentCursorPosition();
     }
+
+    public void setCalcHeadersController(CalcHeadersController calcHeadersController) {
+        mDocumentOverlayView.setCalcHeadersController(calcHeadersController);
+    }
+
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/android/source/src/java/org/libreoffice/overlay/DocumentOverlayView.java b/android/source/src/java/org/libreoffice/overlay/DocumentOverlayView.java
index 6afd71309d1d..7d5ab1972d39 100644
--- a/android/source/src/java/org/libreoffice/overlay/DocumentOverlayView.java
+++ b/android/source/src/java/org/libreoffice/overlay/DocumentOverlayView.java
@@ -67,6 +67,7 @@ public class DocumentOverlayView extends View implements View.OnTouchListener {
     private PageNumberRect mPageNumberRect;
     private boolean mPageNumberAvailable = false;
     private int previousIndex = 0; // previous page number, used to compare with the current
+    private CalcHeadersController mCalcHeadersController;
 
     public DocumentOverlayView(Context context) {
         super(context);
@@ -217,6 +218,9 @@ public class DocumentOverlayView extends View implements View.OnTouchListener {
 
         mGraphicSelection.draw(canvas);
 
+        if (mCalcHeadersController != null) {
+            mCalcHeadersController.showHeaders();
+        }
     }
 
     /**
@@ -450,6 +454,10 @@ public class DocumentOverlayView extends View implements View.OnTouchListener {
     public RectF getCurrentCursorPosition() {
         return mCursor.mPosition;
     }
+
+    public void setCalcHeadersController(CalcHeadersController calcHeadersController) {
+        mCalcHeadersController = calcHeadersController;
+    }
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java b/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java
index b834fa0798d5..d3568216c159 100644
--- a/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java
+++ b/android/source/src/java/org/mozilla/gecko/gfx/JavaPanZoomController.java
@@ -984,6 +984,9 @@ class JavaPanZoomController
 
     @Override
     public boolean onDoubleTap(MotionEvent motionEvent) {
+        if (!mTarget.getZoomConstraints().getAllowDoubleTapZoom()) {
+            return true;
+        }
         // Double tap zooms in or out depending on the current zoom factor
         PointF pointOfTap = getMotionInDocumentCoordinates(motionEvent);
         ImmutableViewportMetrics metrics = getMetrics();