Changeset 149137 in webkit

Timestamp:

Apr 25, 2013 1:02:55 PM (11 years ago)

Author:

commit-queue@webkit.org

Message:

[BlackBerry] Make scroll position adjustment work with pages with fixed position elements.
​https://bugs.webkit.org/show_bug.cgi?id=115178

Patch by Iris Wu <​shuwu@blackberry.com> on 2013-04-25
Reviewed by Rob Buis.

PR 308796

Currently the position WebPage::adjustDocumentScrollPosition adjusts is the top
left point of the viewport.
On the page with fixed position elements, we want it to adjust the position beneath
the fixed elements so it can be always visible.

The basic idea is:

1. Detect if there are fixed position elements before going through ProximityDetector.
2. If the fixed element exists, calculate its the size and the actual visible position

beneath it.

3. Pass the position to ProximityDetector. Then according to the new position we get,

calculate the top left position of the viewport (final scroll position).

• Api/WebPage.cpp:

(BlackBerry::WebKit::WebPage::fixedElementSizeDelta):
(WebKit):

• Api/WebPage.h:
• Api/WebPageCompositor.cpp:

(BlackBerry::WebKit::WebPageCompositorPrivate::findFixedElementRect):
(WebKit):

• Api/WebPageCompositor_p.h:

(WebPageCompositorPrivate):

Location:

trunk/Source/WebKit/blackberry

Files:

• Api/WebPage.cpp (modified) (1 diff)
• Api/WebPage.h (modified) (1 diff)
• Api/WebPageCompositor.cpp (modified) (1 diff)
• Api/WebPageCompositor_p.h (modified) (1 diff)
• ChangeLog (modified) (1 diff)

trunk/Source/WebKit/blackberry/Api/WebPage.cpp

@@ -5239 +5239 @@
 }
 
+Platform::IntSize WebPage::fixedElementSizeDelta()
+{
+    ASSERT(userInterfaceThreadMessageClient()->isCurrentThread());
+
+    // Traverse the layer tree and find the fixed element rect if there is one.
+    IntRect fixedElementRect;
+    if (d->compositor() && d->compositor()->rootLayer())
+        d->compositor()->findFixedElementRect(d->compositor()->rootLayer(), fixedElementRect);
+
+    // Ignore the fixed element if it is not at the top of page.
+    if (!fixedElementRect.isEmpty() && !fixedElementRect.y())
+        return Platform::IntSize(0, fixedElementRect.height());
+    return Platform::IntSize();
+}
+
 bool WebPagePrivate::compositorDrawsRootLayer() const
 {

trunk/Source/WebKit/blackberry/Api/WebPage.h

@@ -333 +333 @@
 
     Platform::IntPoint adjustDocumentScrollPosition(const Platform::IntPoint& documentScrollPosition, const Platform::IntRect& documentPaddingRect);
+    Platform::IntSize fixedElementSizeDelta();
 
     // FIXME: Needs API review on this header. See PR #120402.

trunk/Source/WebKit/blackberry/Api/WebPageCompositor.cpp

@@ -281 +281 @@
 }
 
+void WebPageCompositorPrivate::findFixedElementRect(LayerCompositingThread* layer, WebCore::IntRect& fixedElementRect)
+{
+    if ((layer->hasFixedContainer() || layer->isFixedPosition() || layer->hasFixedAncestorInDOMTree()) && layer->layerRenderer()) {
+        IntRect fixedRect = layer->layerRenderer()->toPixelViewportCoordinates(layer->getDrawRect());
+        // FIXME: It's possible that the rects don't intersect now, but will be connected by a fixed rect found later.
+        // We need to handle it as well.
+        if (fixedElementRect.isEmpty() || fixedElementRect.intersects(fixedRect)) // Unite rects if they intersect each other.
+            fixedElementRect.unite(fixedRect);
+        else if (fixedRect.y() < fixedElementRect.y()) // Replace the fixedElementRect with fixedRect if fixedRect is above it (closer to top).
+            fixedElementRect = fixedRect;
+    }
+
+    const Vector<RefPtr<LayerCompositingThread> >& sublayers = layer->getSublayers();
+    for (size_t i = 0; i < sublayers.size(); i++)
+        findFixedElementRect(sublayers[i].get(), fixedElementRect);
+}
+
 WebPageCompositor::WebPageCompositor(WebPage* page, WebPageCompositorClient* client)
 {

trunk/Source/WebKit/blackberry/Api/WebPageCompositor_p.h

@@ -105 +105 @@
     void removeOverlay(WebCore::LayerCompositingThread*);
 
+    void findFixedElementRect(WebCore::LayerCompositingThread*, WebCore::IntRect&);
+
 protected:
     WebPageCompositorPrivate(WebPagePrivate*, WebPageCompositorClient*);

trunk/Source/WebKit/blackberry/ChangeLog

@@ +1 @@
+2013-04-25  Iris Wu  <shuwu@blackberry.com>
+
+        [BlackBerry] Make scroll position adjustment work with pages with fixed position elements.
+        https://bugs.webkit.org/show_bug.cgi?id=115178
+
+        Reviewed by Rob Buis.
+
+        PR 308796
+
+        Currently the position WebPage::adjustDocumentScrollPosition adjusts is the top
+        left point of the viewport.
+        On the page with fixed position elements, we want it to adjust the position beneath
+        the fixed elements so it can be always visible.
+
+        The basic idea is:
+        1.  Detect if there are fixed position elements before going through ProximityDetector.
+        2.  If the fixed element exists, calculate its the size and the actual visible position
+            beneath it.
+        3.  Pass the position to ProximityDetector. Then according to the new position we get,
+            calculate the top left position of the viewport (final scroll position).
+
+        * Api/WebPage.cpp:
+        (BlackBerry::WebKit::WebPage::fixedElementSizeDelta):
+        (WebKit):
+        * Api/WebPage.h:
+        * Api/WebPageCompositor.cpp:
+        (BlackBerry::WebKit::WebPageCompositorPrivate::findFixedElementRect):
+        (WebKit):
+        * Api/WebPageCompositor_p.h:
+        (WebPageCompositorPrivate):
+
 2013-04-25  Mike Lattanzio  <mlattanzio@blackberry.com>