Double buffering for layers

bug:5309934

Defer picture changes and invalidations when:
1) a tiled texture hasn't completed painting
2) the user is scrolling (done in PaintedSurface)

Remaining issues:
Should block updates on zooming

Change-Id: I60ee722e651f96e95a4ac0e819999fc1589037c3

1 files changed, 120 insertions, 0 deletions

diff --git a/Source/WebCore/platform/graphics/android/UpdateManager.cpp b/Source/WebCore/platform/graphics/android/UpdateManager.cpp
new file mode 100644
index 0000000..1c20f1f
--- /dev/null
+++ b/Source/WebCore/platform/graphics/android/UpdateManager.cpp
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2011, The Android Open Source Project
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "PaintedSurface.h"
+
+#include "LayerAndroid.h"
+#include "TilesManager.h"
+#include "SkCanvas.h"
+#include "SkPicture.h"
+
+#include <cutils/log.h>
+#include <wtf/CurrentTime.h>
+#include <wtf/text/CString.h>
+
+#undef XLOGC
+#define XLOGC(...) android_printLog(ANDROID_LOG_DEBUG, "UpdateManager", __VA_ARGS__)
+
+#ifdef DEBUG
+
+#undef XLOG
+#define XLOG(...) android_printLog(ANDROID_LOG_DEBUG, "UpdateManager", __VA_ARGS__)
+
+#else
+
+#undef XLOG
+#define XLOG(...)
+
+#endif // DEBUG
+
+namespace WebCore {
+
+UpdateManager::UpdateManager()
+    : m_paintingPicture(0)
+    , m_deferredPicture(0)
+{
+}
+
+UpdateManager::~UpdateManager()
+{
+    SkSafeUnref(m_paintingPicture);
+    SkSafeUnref(m_deferredPicture);
+}
+
+void UpdateManager::swap()
+{
+    m_paintingInval.op(m_deferredInval, SkRegion::kUnion_Op);
+    m_deferredInval.setEmpty();
+
+    android::Mutex::Autolock lock(m_paintingPictureSync);
+    if (m_deferredPicture) {
+        XLOG("unlock of updatemanager %p, was painting %p, now painting %p",
+             this, m_paintingPicture, m_deferredPicture);
+        SkSafeUnref(m_paintingPicture);
+        m_paintingPicture = m_deferredPicture;
+        m_deferredPicture = 0;
+    }
+}
+
+void UpdateManager::updateInval(const SkRegion& invalRegion)
+{
+    m_deferredInval.op(invalRegion, SkRegion::kUnion_Op);
+}
+
+void UpdateManager::updatePicture(SkPicture* picture)
+{
+    SkSafeRef(picture);
+    SkSafeUnref(m_deferredPicture);
+    m_deferredPicture = picture;
+}
+
+bool UpdateManager::paint(BaseTile* tile, SkCanvas* canvas, unsigned int* pictureUsed)
+{
+    m_paintingPictureSync.lock();
+    SkPicture* picture = m_paintingPicture;
+    SkSafeRef(picture);
+    m_paintingPictureSync.unlock();
+
+    XLOG("UpdateManager %p painting with picture %p", this, picture);
+
+    if (!picture)
+        return false;
+
+    canvas->drawPicture(*picture);
+
+    // TODO: visualization layer diagonals
+
+    SkSafeUnref(picture);
+    return true;
+}
+
+
+void UpdateManager::clearPaintingInval()
+{
+    m_paintingInval.setEmpty();
+}
+
+} // namespace WebCore