Set a fixed layout size only if the container view has a WRAP_CONTENT layout mode.
Cherry pick http://crrev.com/35403002
> Using the measureSpec from the onMeasure callback to decide whether to set a
> fixed layout size or not has proven to be a bit unpredictable. Changing the
> code to look at the LayoutParams instead.
>
> BUG=None
> TEST=AndroidWebViewTest
> // android_webview-only, trybots were happy.
> NOTRY=true
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=231815
BUG: 11128702
Change-Id: I08093b50965148632ca7ed8298decb55d4a6b505
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index 14b8014..c429bc0 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -320,6 +320,12 @@
if (mNativeAwContents == 0) return;
nativeSetFixedLayoutSize(mNativeAwContents, widthDip, heightDip);
}
+
+ @Override
+ public boolean isLayoutParamsHeightWrapContent() {
+ return mContainerView.getLayoutParams() != null &&
+ mContainerView.getLayoutParams().height == ViewGroup.LayoutParams.WRAP_CONTENT;
+ }
}
//--------------------------------------------------------------------------------------------
diff --git a/android_webview/java/src/org/chromium/android_webview/AwLayoutSizer.java b/android_webview/java/src/org/chromium/android_webview/AwLayoutSizer.java
index 527c39e..3b996a0 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwLayoutSizer.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwLayoutSizer.java
@@ -58,6 +58,7 @@
void requestLayout();
void setMeasuredDimension(int measuredWidth, int measuredHeight);
void setFixedLayoutSize(int widthDip, int heightDip);
+ boolean isLayoutParamsHeightWrapContent();
}
/**
@@ -225,14 +226,34 @@
// call from onSizeChanged, since onSizeChanged won't fire if the view's physical size doesn't
// change.
private void updateFixedLayoutSize(int w, int h, float pageScaleFactor) {
- // If the WebView's measuredDimension depends on the size of it's contents (which is the
- // case if any of the measurement modes are AT_MOST or UNSPECIFIED) the viewport size
- // cannot be directly calculated from the size as that can result in the layout being
- // unstable or unpredictable.
- // If both the width and height are fixed (specified by the parent) then content size
+ boolean wrapContentForHeight = mDelegate.isLayoutParamsHeightWrapContent();
+ // If the WebView's size in the Android view system depends on the size of its contents then
+ // the viewport size cannot be directly calculated from the WebView's physical size as that
+ // can result in the layout being unstable (for example loading the following contents
+ // <div style="height:150%">a</a>
+ // would cause the WebView to indefinitely attempt to increase its height by 50%).
+ // If both the width and height are fixed (specified by the parent View) then content size
// changes will not cause subsequent layout passes and so we don't need to do anything
// special.
- if ((mWidthMeasurementIsFixed && mHeightMeasurementIsFixed) || pageScaleFactor == 0) {
+ // We assume the width is 'fixed' if the parent View specified an EXACT or an AT_MOST
+ // measureSpec for the width (in which case the AT_MOST upper bound is the width).
+ // That means that the WebView will ignore LayoutParams.width set to WRAP_CONTENT and will
+ // instead try to take up as much width as possible. This is necessary because it's not
+ // practical to do web layout without a set width.
+ // For height the behavior is different because for a given width it is possible to
+ // calculate the minimum height required to display all of the content. As such the WebView
+ // can size itself vertically to match the content height. Because certain container views
+ // (LinearLayout with a WRAP_CONTENT height, for example) can result in onMeasure calls with
+ // both EXACTLY and AT_MOST height measureSpecs it is not possible to infer the sizing
+ // policy for the whole subtree based on the parameters passed to the onMeasure call.
+ // For that reason the LayoutParams.height property of the WebView is used. This behaves
+ // more predictably and means that toggling the fixedLayoutSize mode (which can have
+ // significant impact on how the web contents is laid out) is a direct consequence of the
+ // developer's choice. The downside is that it could result in the Android layout being
+ // unstable if a parent of the WebView has a wrap_content height while the WebView itself
+ // has height set to match_parent. Unfortunately addressing this edge case is costly so it
+ // will have to stay as is (this is compatible with Classic behavior).
+ if ((mWidthMeasurementIsFixed && !wrapContentForHeight) || pageScaleFactor == 0) {
setFixedLayoutSize(0, 0);
return;
}
diff --git a/android_webview/javatests/src/org/chromium/android_webview/test/AwLayoutSizerTest.java b/android_webview/javatests/src/org/chromium/android_webview/test/AwLayoutSizerTest.java
index 5d8b56b..357e922 100644
--- a/android_webview/javatests/src/org/chromium/android_webview/test/AwLayoutSizerTest.java
+++ b/android_webview/javatests/src/org/chromium/android_webview/test/AwLayoutSizerTest.java
@@ -20,6 +20,7 @@
public int measuredHeight;
public int fixedLayoutWidth;
public int fixedLayoutHeight;
+ public boolean heightWrapContent;
@Override
public void requestLayout() {
@@ -38,6 +39,11 @@
fixedLayoutWidth = widthDip;
fixedLayoutHeight = heightDip;
}
+
+ @Override
+ public boolean isLayoutParamsHeightWrapContent() {
+ return heightWrapContent;
+ }
}
private static final int FIRST_CONTENT_WIDTH = 101;
@@ -382,7 +388,7 @@
@SmallTest
@Feature({"AndroidWebView"})
- public void testViewportWithWrapContentMeasureSpec() {
+ public void testViewportWithUnspecifiedMeasureSpec() {
AwLayoutSizer layoutSizer = new AwLayoutSizer();
LayoutSizerDelegate delegate = new LayoutSizerDelegate();
layoutSizer.setDelegate(delegate);
@@ -391,7 +397,6 @@
final int pageScale = 2;
final int dipAndPageScale = (int) (dipScale * pageScale);
-
int contentWidth = 800;
int contentHeight = 400;
int atMostWidth = contentWidth * dipAndPageScale;
@@ -431,6 +436,41 @@
@SmallTest
@Feature({"AndroidWebView"})
+ public void testViewportWithAtMostMeasureSpec() {
+ AwLayoutSizer layoutSizer = new AwLayoutSizer();
+ LayoutSizerDelegate delegate = new LayoutSizerDelegate();
+ delegate.heightWrapContent = true;
+ layoutSizer.setDelegate(delegate);
+
+ final float dipScale = 1.5f;
+ final int pageScale = 2;
+ final int dipAndPageScale = (int) (dipScale * pageScale);
+
+ int contentWidth = 800;
+ int contentHeight = 400;
+ int contentWidthPix = contentWidth * dipAndPageScale;
+ int contentHeightPix = contentHeight * dipAndPageScale;
+
+ layoutSizer.setDIPScale(dipScale);
+ layoutSizer.onContentSizeChanged(contentWidth, contentHeight);
+ layoutSizer.onPageScaleChanged(pageScale);
+ layoutSizer.onMeasure(MeasureSpec.makeMeasureSpec(contentWidthPix, MeasureSpec.EXACTLY),
+ MeasureSpec.makeMeasureSpec(contentHeightPix * 2, MeasureSpec.AT_MOST));
+
+ assertTrue(delegate.setMeasuredDimensionCalled);
+ int measuredWidth = delegate.measuredWidth & View.MEASURED_SIZE_MASK;
+ int measuredHeight = delegate.measuredHeight & View.MEASURED_SIZE_MASK;
+
+ int sizeWidth = measuredWidth;
+ int sizeHeight = measuredHeight;
+ layoutSizer.onSizeChanged(sizeWidth, sizeHeight, 0, 0);
+
+ assertEquals(contentWidth, delegate.fixedLayoutWidth);
+ assertEquals(AwLayoutSizer.FIXED_LAYOUT_HEIGHT, delegate.fixedLayoutHeight);
+ }
+
+ @SmallTest
+ @Feature({"AndroidWebView"})
public void testFixedLayoutViewportGoesBackToZeroWithWrapContentMeasureSpec() {
AwLayoutSizer layoutSizer = new AwLayoutSizer();
LayoutSizerDelegate delegate = new LayoutSizerDelegate();
@@ -465,6 +505,7 @@
public void testFixedLayoutSizeUpdatedOnPageScaleChangeItNoLayoutRequest() {
AwLayoutSizer layoutSizer = new AwLayoutSizer();
LayoutSizerDelegate delegate = new LayoutSizerDelegate();
+ delegate.heightWrapContent = true;
layoutSizer.setDelegate(delegate);
layoutSizer.setDIPScale(DIP_SCALE);
@@ -514,4 +555,24 @@
assertEquals(fixedLayoutWidth * 2, delegate.fixedLayoutWidth);
}
+
+ @SmallTest
+ @Feature({"AndroidWebView"})
+ public void testFixedLayoutSizeDoesNotDependOnMeasureSpec() {
+ AwLayoutSizer layoutSizer = new AwLayoutSizer();
+ LayoutSizerDelegate delegate = new LayoutSizerDelegate();
+ delegate.heightWrapContent = false;
+ layoutSizer.setDelegate(delegate);
+ layoutSizer.setDIPScale(DIP_SCALE);
+
+ layoutSizer.onContentSizeChanged(TOO_LARGE_CONTENT_SIZE, TOO_LARGE_CONTENT_SIZE);
+ layoutSizer.onPageScaleChanged(INITIAL_PAGE_SCALE);
+ layoutSizer.onMeasure(
+ MeasureSpec.makeMeasureSpec(AT_MOST_MEASURE_SIZE, MeasureSpec.AT_MOST),
+ MeasureSpec.makeMeasureSpec(AT_MOST_MEASURE_SIZE, MeasureSpec.AT_MOST));
+ layoutSizer.onSizeChanged(AT_MOST_MEASURE_SIZE, AT_MOST_MEASURE_SIZE, 0, 0);
+
+ assertEquals(0, delegate.fixedLayoutWidth);
+ assertEquals(0, delegate.fixedLayoutHeight);
+ }
}
