Bug 792410 - Scale tab thumbnails from the upper left corner. r=sriram

mobile/android/base/GeckoViewsFactory.java

@@ -5,6 +5,7 @@
 package org.mozilla.gecko;
 
 import org.mozilla.gecko.gfx.LayerView;
+import org.mozilla.gecko.widget.ThumbnailView;
 
 import android.content.Context;
 import android.text.TextUtils;
@@ -110,6 +111,8 @@ public final class GeckoViewsFactory implements LayoutInflater.Factory {
                 return new GeckoTextSwitcher(context, attrs);
             else if (TextUtils.equals(viewName, "TextView"))
                 return new GeckoTextView(context, attrs);
+            else if (TextUtils.equals(viewName, "widget.ThumbnailView"))
+                return new ThumbnailView(context, attrs);
             else
                 Log.d(LOGTAG, "Warning: unknown custom view: " + viewName);
         }

mobile/android/base/Makefile.in

@@ -183,6 +183,7 @@ FENNEC_JAVA_FILES = \
   ui/SimpleScaleGestureDetector.java \
   ui/SubdocumentScrollHelper.java \
   widget/DateTimePicker.java \
+  widget/ThumbnailView.java \
   GeckoNetworkManager.java \
   GeckoScreenOrientationListener.java \
   UpdateService.java \

mobile/android/base/resources/layout-xlarge-v11/tabs_row.xml

@@ -22,15 +22,14 @@
                         android:layout_weight="1.0"
                         android:layout_margin="10dip">
 
-            <ImageView android:id="@+id/thumbnail"
+            <org.mozilla.gecko.widget.ThumbnailView android:id="@+id/thumbnail"
                        android:layout_width="@dimen/tab_thumbnail_width"
                        android:layout_height="@dimen/tab_thumbnail_height"
                        android:layout_marginLeft="1dip"
                        android:layout_marginTop="1dip"
                        android:layout_alignParentLeft="true"
                        android:layout_centerVertical="true"
-                       android:src="@drawable/tab_thumbnail_default"
-                       android:scaleType="centerCrop"/>
+                       android:src="@drawable/tab_thumbnail_default"/>
 
             <ImageView android:id="@+id/shadow"
                        android:layout_width="138dip"

mobile/android/base/resources/layout/tabs_row.xml

@@ -17,15 +17,14 @@
                     android:layout_height="wrap_content"
                     android:layout_margin="10dip">
 
-        <ImageView android:id="@+id/thumbnail"
+        <org.mozilla.gecko.widget.ThumbnailView android:id="@+id/thumbnail"
                    android:layout_width="@dimen/tab_thumbnail_width"
                    android:layout_height="@dimen/tab_thumbnail_height"
                    android:layout_marginLeft="1dip"
                    android:layout_marginTop="1dip"
                    android:layout_alignParentLeft="true"
                    android:layout_centerVertical="true"
-                   android:src="@drawable/tab_thumbnail_default"
-                   android:scaleType="centerCrop"/>
+                   android:src="@drawable/tab_thumbnail_default"/>
 
         <ImageView android:id="@+id/shadow"
                    android:layout_width="138dip"

mobile/android/base/widget/ThumbnailView.java

@@ -0,0 +1,68 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.widget;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.drawable.Drawable;
+import android.graphics.Matrix;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.widget.ImageView;
+
+/* Special version of ImageView for thumbnails. Scales a thumbnail so that it maintains its aspect
+ * ratio and so that the images width and height are the same size or greater than the view size
+ */
+public class ThumbnailView extends ImageView {
+    private static final String LOGTAG = "GeckoThumbnailView";
+    private Matrix mMatrix = null;
+    private int mWidthSpec = -1;
+    private int mHeightSpec = -1;
+
+    public ThumbnailView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mMatrix = new Matrix();
+    }
+
+    @Override
+    public void onDraw(Canvas canvas) {
+        Drawable d = getDrawable();
+        if (mMatrix == null) {
+            int w1 = d.getIntrinsicWidth();
+            int h1 = d.getIntrinsicHeight();
+            int w2 = getWidth();
+            int h2 = getHeight();
+    
+            float scale = 1.0f;
+            if (w2/h2 < w1/h1) {
+                scale = (float)h2/h1;
+            } else {
+                scale = (float)w2/w1;
+            }
+
+            mMatrix.reset();
+            mMatrix.setScale(scale, scale);
+        }
+
+        int saveCount = canvas.save();
+        canvas.concat(mMatrix);
+        d.draw(canvas);
+        canvas.restoreToCount(saveCount);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
+        // OnLayout.changed isn't a reliable measure of whether or not the size of this view has changed
+        // neither is onSizeChanged called often enough. Instead, we track changes in size ourselves, and
+        // only invalidate this matrix if we have a new width/height spec
+        if (widthMeasureSpec != mWidthSpec || heightMeasureSpec != mHeightSpec) {
+            mWidthSpec = widthMeasureSpec;
+            mHeightSpec = heightMeasureSpec;
+            mMatrix = null;
+        }
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+    }
+}