Update selection handle bitmaps in AW if DIP scale changes

android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java

Index: android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java
diff --git a/android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java b/android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java
index 3ff98343cea2b2c478152fda964b7dad672b6edb..1e809d1701303e2faae5d694bfe214030b4bd61d 100644
--- a/android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java
+++ b/android_webview/java/src/org/chromium/android_webview/PopupTouchHandleDrawable.java
@@ -6,6 +6,7 @@ package org.chromium.android_webview;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
+import android.content.res.Configuration;
 import android.graphics.Canvas;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
@@ -27,6 +28,8 @@ import org.chromium.content.browser.PositionObserver;
 import org.chromium.content.browser.ViewPositionObserver;
 import org.chromium.content.browser.input.HandleViewResources;
 import org.chromium.content_public.browser.GestureStateListener;
+import org.chromium.ui.base.WindowAndroid;
+import org.chromium.ui.display.DisplayAndroid.DisplayAndroidObserver;
 import org.chromium.ui.touch_selection.TouchHandleOrientation;
 
 import java.lang.reflect.InvocationTargetException;
@@ -40,7 +43,20 @@ import java.lang.reflect.Method;
  *
  */
 @JNINamespace("android_webview")
-public class PopupTouchHandleDrawable extends View {
+public class PopupTouchHandleDrawable extends View implements DisplayAndroidObserver {
+    @Override
+    public void onRotationChanged(int rotation) {}
+
+    @Override
+    public void onDIPScaleChanged(float dipScale) {
+        if (mDeviceScale != dipScale) {
+            mDeviceScale = dipScale;
+
+            // Postpone update till onConfigurationChanged()
+            mNeedsUpdateDrawable = true;
+        }
+    }
+
     private final PopupWindow mContainer;
     private final PositionObserver.Listener mParentPositionListener;
     private ContentViewCore mContentViewCore;
@@ -68,6 +84,8 @@ public class PopupTouchHandleDrawable extends View {
 
     private int mOrientation = TouchHandleOrientation.UNDEFINED;
 
+    private float mDeviceScale;
+
     // Length of the delay before fading in after the last page movement.
     private static final int MOVING_FADE_IN_DELAY_MS = 300;
     private static final int FADE_IN_DURATION_MS = 200;
@@ -98,6 +116,8 @@ public class PopupTouchHandleDrawable extends View {
     private Runnable mInvalidationRunnable;
     private boolean mHasPendingInvalidate;
 
+    private boolean mNeedsUpdateDrawable;
+
     // List of drawables used to inform them of the container view switching.
     private final ObserverList<PopupTouchHandleDrawable> mDrawableObserverList;
 
@@ -108,8 +128,12 @@ public class PopupTouchHandleDrawable extends View {
         mDrawableObserverList.addObserver(this);
 
         mContentViewCore = contentViewCore;
-        mContainer = new PopupWindow(mContentViewCore.getWindowAndroid().getContext().get(),
-                null, android.R.attr.textSelectHandleWindowStyle);
+
+        WindowAndroid windowAndroid = mContentViewCore.getWindowAndroid();

[boliu, 2016/11/29 03:35:43]

need null check for windowAndroid

[Tima Vaisburd, 2016/11/29 17:14:52]

Without windowAndroid we apparently cannot create |mContainer|. Would it be ok
to just return here and leave the object not fully constructed? It seems the
original code assumes that |windowAndroid| can not be null at this point?

[boliu, 2016/11/29 17:22:52]

No, the better thing would be to not create the object at all.

But otoh, this file has been moved to webview code, and getWindowAndroid will
never be null. So never mind about the null check

+        mDeviceScale = windowAndroid.getDisplay().getDipScale();
+
+        mContainer = new PopupWindow(
+                windowAndroid.getContext().get(), null, android.R.attr.textSelectHandleWindowStyle);
         mContainer.setSplitTouchEnabled(true);
         mContainer.setClippingEnabled(false);
 
@@ -251,6 +275,19 @@ public class PopupTouchHandleDrawable extends View {
         if (orientationChanged || mirroringChanged) scheduleInvalidate();
     }
 
+    @SuppressLint("NewApi")
+    private void updateDrawableAndRequestLayout() {
+        mNeedsUpdateDrawable = false;
+
+        if (mDrawable == null) return;
+
+        mDrawable = getHandleDrawable(getContext(), mOrientation);
+
+        if (mDrawable != null) mDrawable.setAlpha((int) (255 * mAlpha));
+
+        if (!isInLayout()) requestLayout();
+    }
+
     private void updateParentPosition(int parentPositionX, int parentPositionY) {
         if (mParentPositionX == parentPositionX && mParentPositionY == parentPositionY) return;
         mParentPositionX = parentPositionX;
@@ -259,13 +296,11 @@ public class PopupTouchHandleDrawable extends View {
     }
 
     private int getContainerPositionX() {
-        final float deviceScale = mContentViewCore.getDeviceScaleFactor();
-        return mParentPositionX + (int) (mOriginXDip * deviceScale);
+        return mParentPositionX + (int) (mOriginXDip * mDeviceScale);
     }
 
     private int getContainerPositionY() {
-        final float deviceScale = mContentViewCore.getDeviceScaleFactor();
-        return mParentPositionY + (int) (mOriginYDip * deviceScale);
+        return mParentPositionY + (int) (mOriginYDip * mDeviceScale);
     }
 
     private void updatePosition() {
@@ -274,11 +309,10 @@ public class PopupTouchHandleDrawable extends View {
     }
 
     private boolean isShowingAllowed() {
-        final float deviceScale = mContentViewCore.getDeviceScaleFactor();
         // mOriginX/YDip * deviceScale is the distance of the handler drawable from the top left of
         // the containerView (the WebView).
         return mAttachedToWindow && mVisible && mFocused && !mScrolling && !mTemporarilyHidden
-                && isPositionVisible(mOriginXDip * deviceScale, mOriginYDip * deviceScale);
+                && isPositionVisible(mOriginXDip * mDeviceScale, mOriginYDip * mDeviceScale);
     }
 
     // Adapted from android.widget.Editor#isPositionVisible.
@@ -446,6 +480,16 @@ public class PopupTouchHandleDrawable extends View {
     }
 
     @Override
+    protected void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+
+        // Update the drawable when the configuration with the new density comes.
+        if (mNeedsUpdateDrawable && mDeviceScale == getResources().getDisplayMetrics().density) {
+            updateDrawableAndRequestLayout();
+        }
+    }
+
+    @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         if (mDrawable == null) {
             setMeasuredDimension(0, 0);
@@ -475,11 +519,22 @@ public class PopupTouchHandleDrawable extends View {
         super.onAttachedToWindow();
         mAttachedToWindow = true;
         onVisibilityInputChanged();
+
+        WindowAndroid windowAndroid = mContentViewCore.getWindowAndroid();
+        if (windowAndroid != null) {
+            windowAndroid.getDisplay().addObserver(this);
+            mDeviceScale = windowAndroid.getDisplay().getDipScale();

[Tima Vaisburd, 2016/11/29 02:55:58]

Here I just assigned the value directly instead of calling onDIPScaleChanged().

+            updateDrawableAndRequestLayout();
+        }
     }
 
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
+
+        WindowAndroid windowAndroid = mContentViewCore.getWindowAndroid();
+        if (windowAndroid != null) windowAndroid.getDisplay().removeObserver(this);
+
         mAttachedToWindow = false;
         onVisibilityInputChanged();
     }
@@ -555,15 +610,13 @@ public class PopupTouchHandleDrawable extends View {
     @CalledByNative
     private float getVisibleWidthDip() {
         if (mDrawable == null) return 0;
-        if (mContentViewCore == null) return 0;
-        return mDrawable.getIntrinsicWidth() / mContentViewCore.getDeviceScaleFactor();
+        return mDrawable.getIntrinsicWidth() / mDeviceScale;
     }
 
     @CalledByNative
     private float getVisibleHeightDip() {
         if (mDrawable == null) return 0;
-        if (mContentViewCore == null) return 0;
-        return mDrawable.getIntrinsicHeight() / mContentViewCore.getDeviceScaleFactor();
+        return mDrawable.getIntrinsicHeight() / mDeviceScale;
     }
 
     public void onContainerViewChanged(ViewGroup newContainerView) {