Add BlimpView to a Chrome tab when Blimp is enabled.

blimp/client/core/contents/android/java/src/org/chromium/blimp/core/contents/BlimpView.java

Index: blimp/client/core/contents/android/java/src/org/chromium/blimp/core/contents/BlimpView.java
diff --git a/blimp/client/core/contents/android/java/src/org/chromium/blimp/core/contents/BlimpView.java b/blimp/client/core/contents/android/java/src/org/chromium/blimp/core/contents/BlimpView.java
new file mode 100644
index 0000000000000000000000000000000000000000..c459d81c0203a5d4b86491931a7de86a278b76f6
--- /dev/null
+++ b/blimp/client/core/contents/android/java/src/org/chromium/blimp/core/contents/BlimpView.java
@@ -0,0 +1,127 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.blimp.core.contents;
+
+import android.content.Context;
+import android.view.MotionEvent;
+import android.view.View;
+import android.widget.FrameLayout;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.ui.base.ViewAndroidDelegate;
+import org.chromium.ui.base.WindowAndroid;
+
+/**
+ * A {@link View} that will visually represent the Blimp rendered content.
+ */
+@JNINamespace("blimp::client")
+public class BlimpView extends FrameLayout {
+    @CalledByNative
+    private static BlimpView create(long nativeBlimpView, WindowAndroid window) {
+        Context context = window.getContext().get();
+        if (context == null) throw new AssertionError("WindowAndroid must have a valid context.");
+        return new BlimpView(nativeBlimpView, context);
+    }
+
+    /**
+     * Pointer to the native JNI bridge.
+     */
+    private long mNativeBlimpViewPtr;
+
+    /**
+     * Builds a new {@link BlimpView}.
+     * @param nativeBlimpView the pointer to the native BlimpView.
+     * @param context A {@link Context} instance.
+     */
+    private BlimpView(long nativeBlimpView, Context context) {
+        super(context);
+        setFocusable(true);
+        setFocusableInTouchMode(true);
+        mNativeBlimpViewPtr = nativeBlimpView;
+    }
+
+    // View overrides.
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        if (mNativeBlimpViewPtr == 0) return;
+        nativeOnSizeChanged(
+                mNativeBlimpViewPtr, w, h, getContext().getResources().getDisplayMetrics().density);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        if (mNativeBlimpViewPtr == 0) return false;
+
+        if (!hasValidTouchEventActionForNative(event)) return false;
+
+        int pointerCount = event.getPointerCount();
+
+        float[] touchMajor = {event.getTouchMajor(), pointerCount > 1 ? event.getTouchMajor(1) : 0};
+        float[] touchMinor = {event.getTouchMinor(), pointerCount > 1 ? event.getTouchMinor(1) : 0};
+
+        for (int i = 0; i < 2; i++) {
+            if (touchMajor[i] < touchMinor[i]) {
+                float tmp = touchMajor[i];
+                touchMajor[i] = touchMinor[i];
+                touchMinor[i] = tmp;
+            }
+        }
+
+        // Native returns whether the event was consumed.
+        return nativeOnTouchEvent(mNativeBlimpViewPtr, event, event.getEventTime(),
+                event.getActionMasked(), pointerCount, event.getHistorySize(),
+                event.getActionIndex(), event.getX(), event.getY(),
+                pointerCount > 1 ? event.getX(1) : 0, pointerCount > 1 ? event.getY(1) : 0,
+                event.getPointerId(0), pointerCount > 1 ? event.getPointerId(1) : -1, touchMajor[0],
+                touchMajor[1], touchMinor[0], touchMinor[1], event.getOrientation(),
+                pointerCount > 1 ? event.getOrientation(1) : 0,
+                event.getAxisValue(MotionEvent.AXIS_TILT),
+                pointerCount > 1 ? event.getAxisValue(MotionEvent.AXIS_TILT, 1) : 0,
+                event.getRawX(), event.getRawY(), event.getToolType(0),
+                pointerCount > 1 ? event.getToolType(1) : MotionEvent.TOOL_TYPE_UNKNOWN,
+                event.getButtonState(), event.getMetaState(),
+                getContext().getResources().getDisplayMetrics().density);
+    }
+
+    @CalledByNative
+    public void clearNativePtr() {
+        mNativeBlimpViewPtr = 0;
+    }
+
+    @CalledByNative
+    private ViewAndroidDelegate createViewAndroidDelegate() {
+        return ViewAndroidDelegate.createBasicDelegate(this);
+    }
+
+    /**
+     * This method inspects the event action of a TouchEvent and returns whether it should be
+     * passed along to native or not.
+     *
+     * Only some actions have any effect on gesture detection, and other actions again have no
+     * corresponding WebTouchEvent type and may confuse the touch pipeline, so they are ignored
+     * completely.
+     *
+     * @return whether this |eventAction| is a valid touch event action for native code.
+     */
+    private static boolean hasValidTouchEventActionForNative(MotionEvent event) {
+        int eventAction = event.getActionMasked();
+        return eventAction == MotionEvent.ACTION_DOWN || eventAction == MotionEvent.ACTION_UP
+                || eventAction == MotionEvent.ACTION_CANCEL
+                || eventAction == MotionEvent.ACTION_MOVE
+                || eventAction == MotionEvent.ACTION_POINTER_DOWN
+                || eventAction == MotionEvent.ACTION_POINTER_UP;
+    }
+
+    private native void nativeOnSizeChanged(
+            long nativeBlimpView, int width, int height, float deviceScaleFactorDpToPx);
+    private native boolean nativeOnTouchEvent(long nativeBlimpView, MotionEvent event, long timeMs,
+            int action, int pointerCount, int historySize, int actionIndex, float x0, float y0,
+            float x1, float y1, int pointerId0, int pointerId1, float touchMajor0,
+            float touchMajor1, float touchMinor0, float touchMinor1, float orientation0,
+            float orientation1, float tilt0, float tilt1, float rawX, float rawY,
+            int androidToolType0, int androidToolType1, int androidButtonState,
+            int androidMetaState, float deviceScaleFactorDpToPx);
+}