Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge "Fix for requestLayout-during-layout inefficiencies"

Browse Source
This commit is contained in:
Chet Haase
2012-12-19 07:43:02 -08:00
committed by Android (Google) Code Review
parent ceab6cbf78 cc699b4fe3
commit 118257517a
2 changed files with 99 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
core/java/android/view/View.java
View File

@@ -15509,17 +15509,27 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
* handle possible request-during-layout errors correctly.</p>
*/
public void requestLayout() {
ViewRootImpl viewRoot = getViewRootImpl();
if (viewRoot != null && viewRoot.isInLayout()) {
viewRoot.requestLayoutDuringLayout(this);
return;
if (mAttachInfo != null && mAttachInfo.mViewRequestingLayout == null) {
// Only trigger request-during-layout logic if this is the view requesting it,
// not the views in its parent hierarchy
ViewRootImpl viewRoot = getViewRootImpl();
if (viewRoot != null && viewRoot.isInLayout()) {
if (!viewRoot.requestLayoutDuringLayout(this)) {
return;
}
}
mAttachInfo.mViewRequestingLayout = this;
}
mPrivateFlags |= PFLAG_FORCE_LAYOUT;
mPrivateFlags |= PFLAG_INVALIDATED;
if (mParent != null && !mParent.isLayoutRequested()) {
mParent.requestLayout();
}
if (mAttachInfo != null && mAttachInfo.mViewRequestingLayout == this) {
mAttachInfo.mViewRequestingLayout = null;
}
}
/**
@@ -17999,6 +18009,12 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
*/
final Point mPoint = new Point();
/**
* Used to track which View originated a requestLayout() call, used when
* requestLayout() is called during layout.
*/
View mViewRequestingLayout;
/**
* Creates a new set of attachment information with the specified
* events handler and thread.

96
core/java/android/view/ViewRootImpl.java
View File

@@ -1894,22 +1894,37 @@ public final class ViewRootImpl implements ViewParent,
}
/**
* Called by {@link android.view.View#requestLayout()} if the view hiearchy is currently
* undergoing a layout pass. requestLayout() should not be called during layout, but if it
* is called anyway, we handle the situation here rather than leave the hierarchy in an
* indeterminate state. The solution is to queue up all requests during layout, apply those
* requests as soon as layout is complete, and then run layout once more immediately. If
* Called by {@link android.view.View#requestLayout()} if the view hierarchy is currently
* undergoing a layout pass. requestLayout() should not generally be called during layout,
* unless the container hierarchy knows what it is doing (i.e., it is fine as long as
* all children in that container hierarchy are measured and laid out at the end of the layout
* pass for that container). If requestLayout() is called anyway, we handle it correctly
* by registering all requesters during a frame as it proceeds. At the end of the frame,
* we check all of those views to see if any still have pending layout requests, which
* indicates that they were not correctly handled by their container hierarchy. If that is
* the case, we clear all such flags in the tree, to remove the buggy flag state that leads
* to blank containers, and force a second request/measure/layout pass in this frame. If
* more requestLayout() calls are received during that second layout pass, we post those
* requests to the next frame, to avoid possible infinite loops.
* requests to the next frame to avoid possible infinite loops.
*
* <p>The return value from this method indicates whether the request should proceed
* (if it is a request during the first layout pass) or should be skipped and posted to the
* next frame (if it is a request during the second layout pass).</p>
*
* @param view the view that requested the layout.
*
* @return true if request should proceed, false otherwise.
*/
void requestLayoutDuringLayout(final View view) {
boolean requestLayoutDuringLayout(final View view) {
if (view.mParent == null || view.mAttachInfo == null) {
// Would not normally trigger another layout, so just let it pass through as usual
return true;
}
if (!mHandlingLayoutInLayoutRequest) {
if (!mLayoutRequesters.contains(view)) {
Log.w("View", "requestLayout() called by " + view + " during layout pass");
mLayoutRequesters.add(view);
}
return true;
} else {
Log.w("View", "requestLayout() called by " + view + " during second layout pass: " +
"posting to next frame");
@@ -1919,6 +1934,7 @@ public final class ViewRootImpl implements ViewParent,
view.requestLayout();
}
});
return false;
}
}
@@ -1937,20 +1953,66 @@ public final class ViewRootImpl implements ViewParent,
Trace.traceBegin(Trace.TRACE_TAG_VIEW, "layout");
try {
host.layout(0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());
mInLayout = false;
int numViewsRequestingLayout = mLayoutRequesters.size();
if (numViewsRequestingLayout > 0) {
// requestLayout() was called during layout: unusual, but try to handle correctly
mHandlingLayoutInLayoutRequest = true;
// requestLayout() was called during layout.
// If no layout-request flags are set on the requesting views, there is no problem.
// If some requests are still pending, then we need to clear those flags and do
// a full request/measure/layout pass to handle this situation.
// Check state of layout flags for all requesters
ArrayList<View> mValidLayoutRequesters = null;
for (int i = 0; i < numViewsRequestingLayout; ++i) {
mLayoutRequesters.get(i).requestLayout();
View view = mLayoutRequesters.get(i);
if ((view.mPrivateFlags & View.PFLAG_FORCE_LAYOUT) == View.PFLAG_FORCE_LAYOUT) {
while (view != null && view.mAttachInfo != null && view.mParent != null &&
(view.mPrivateFlags & View.PFLAG_FORCE_LAYOUT) != 0) {
if ((view.mViewFlags & View.VISIBILITY_MASK) != View.GONE) {
// Only trigger new requests for non-GONE views
Log.w(TAG, "requestLayout() improperly called during " +
"layout: running second layout pass for " + view);
if (mValidLayoutRequesters == null) {
mValidLayoutRequesters = new ArrayList<View>();
}
mValidLayoutRequesters.add(view);
break;
}
if (view.mParent instanceof View) {
view = (View) view.mParent;
} else {
view = null;
}
}
}
}
if (mValidLayoutRequesters != null) {
// Clear flags throughout hierarchy, walking up from each flagged requester
for (int i = 0; i < numViewsRequestingLayout; ++i) {
View view = mLayoutRequesters.get(i);
while (view != null &&
(view.mPrivateFlags & View.PFLAG_FORCE_LAYOUT) != 0) {
view.mPrivateFlags &= ~View.PFLAG_FORCE_LAYOUT;
if (view.mParent instanceof View) {
view = (View) view.mParent;
} else {
view = null;
}
}
}
// Process fresh layout requests, then measure and layout
mHandlingLayoutInLayoutRequest = true;
int numValidRequests = mValidLayoutRequesters.size();
for (int i = 0; i < numValidRequests; ++i) {
mValidLayoutRequesters.get(i).requestLayout();
}
measureHierarchy(host, lp, mView.getContext().getResources(),
desiredWindowWidth, desiredWindowHeight);
mInLayout = true;
host.layout(0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());
mHandlingLayoutInLayoutRequest = false;
}
measureHierarchy(host, lp, mView.getContext().getResources(),
desiredWindowWidth, desiredWindowHeight);
// Now run layout one more time
mInLayout = true;
host.layout(0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());
mHandlingLayoutInLayoutRequest = false;
mLayoutRequesters.clear();
}
} finally {