Improved Pinch-Zoom for PDF

pdf/paint_manager.cc

Index: pdf/paint_manager.cc
diff --git a/pdf/paint_manager.cc b/pdf/paint_manager.cc
index 226994c3b054faa2e8b30af6768d844daa66f51e..01256e2f9e98cc18da693152857be6d952f6cded 100644
--- a/pdf/paint_manager.cc
+++ b/pdf/paint_manager.cc
@@ -23,6 +23,7 @@ PaintManager::PaintManager(pp::Instance* instance,
       callback_factory_(NULL),
       manual_callback_pending_(false),
       flush_pending_(false),
+      flush_requested_(false),
       has_pending_resize_(false),
       graphics_need_to_be_bound_(false),
       pending_device_scale_(1.0),
@@ -89,16 +90,38 @@ void PaintManager::SetSize(const pp::Size& new_size, float device_scale) {
   if (GetEffectiveSize() == new_size &&
       GetEffectiveDeviceScale() == device_scale)
     return;
-
   has_pending_resize_ = true;
   pending_size_ = new_size;
   pending_device_scale_ = device_scale;
 
   view_size_changed_waiting_for_paint_ = true;
-
   Invalidate();
 }
 
+void PaintManager::SetTransform(float scale,
+                            pp::Point origin,
+                            pp::Point translate) {
+  if (!flush_pending_) {
+    graphics_.SetLayerTransform(scale, origin, translate);
+    flush_pending_ = true;
+    flush_requested_ = false;
+    graphics_.Flush(
+        callback_factory_.NewCallback(&PaintManager::OnFlushComplete));
+    scale_ = 1.f;
+    origin_ = pp::Point();
+    transform_ = pp::Point();
+  } else {
+    flush_requested_ = true;
+    graphics_.SetLayerTransform(scale, origin, translate);
+  }
+}
+
+void PaintManager::SetTransform(float scale) {
+  graphics_.SetLayerTransform(scale, pp::Point(), pp::Point());
+
+  EnsureCallbackPending();
+}
+
 void PaintManager::Invalidate() {
   if (graphics_.is_null() && !has_pending_resize_)
     return;
@@ -251,10 +274,8 @@ void PaintManager::DoPaint() {
     graphics_.PaintImageData(
         ready_rect.image_data, ready_rect.offset, ready_rect.rect);
   }
-
   int32_t result = graphics_.Flush(
       callback_factory_.NewCallback(&PaintManager::OnFlushComplete));
-
   // If you trigger this assertion, then your plugin has called Flush()
   // manually. When using the PaintManager, you should not call Flush, it will
   // handle that for you because it needs to know when it can do the next paint
@@ -284,7 +305,12 @@ void PaintManager::DoPaint() {
 void PaintManager::OnFlushComplete(int32_t) {
   DCHECK(flush_pending_);
   flush_pending_ = false;
-
+  // If there was another flush request while flushing we flush again.
+  if (flush_requested_) {
+    flush_requested_ = false;
+    graphics_.Flush(
+        callback_factory_.NewCallback(&PaintManager::OnFlushComplete));
+  }
   // If more paints were enqueued while we were waiting for the flush to
   // complete, execute them now.
   if (aggregator_.HasPendingUpdate())
@@ -294,7 +320,6 @@ void PaintManager::OnFlushComplete(int32_t) {
 void PaintManager::OnManualCallbackComplete(int32_t) {
   DCHECK(manual_callback_pending_);
   manual_callback_pending_ = false;
-
   // Just because we have a manual callback doesn't mean there are actually any
   // invalid regions. Even though we only schedule this callback when something
   // is pending, a Flush callback could have come in before this callback was