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 7811f07d5f6ca36662be9c1089cef10c8a11be26..ea9cc7814679f0c077ce1e0861a83fab2d4fef93 100644
--- a/pdf/paint_manager.cc
+++ b/pdf/paint_manager.cc
@@ -32,6 +32,7 @@ PaintManager::PaintManager(pp::Instance* instance,
       callback_factory_(nullptr),
       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),
@@ -108,6 +109,29 @@ void PaintManager::SetSize(const pp::Size& new_size, float device_scale) {
   Invalidate();
 }
 
+void PaintManager::SetTransform(float scale,
+                                const pp::Point& origin,
+                                const pp::Point& translate,
+                                bool schedule_flush) {
+  if (graphics_.is_null())
+    return;
+
+  graphics_.SetLayerTransform(scale, origin, translate);
+
+  if (!schedule_flush)
+    return;
+
+  if (flush_pending_) {
+    flush_requested_ = true;
+    return;
+  }
+  Flush();
+}
+
+void PaintManager::ClearTransform() {
+  SetTransform(1.f, pp::Point(), pp::Point(), false);
+}
+
 void PaintManager::Invalidate() {
   if (graphics_.is_null() && !has_pending_resize_)
     return;
@@ -261,6 +285,20 @@ void PaintManager::DoPaint() {
         ready_rect.image_data, ready_rect.offset, ready_rect.rect);
   }
 
+  Flush();
+
+  in_paint_ = false;
+  first_paint_ = false;
+
+  if (graphics_need_to_be_bound_) {
+    instance_->BindGraphics(graphics_);
+    graphics_need_to_be_bound_ = false;
+  }
+}
+
+void PaintManager::Flush() {
+  flush_requested_ = false;
+
   int32_t result = graphics_.Flush(
       callback_factory_.NewCallback(&PaintManager::OnFlushComplete));
 
@@ -280,14 +318,6 @@ void PaintManager::DoPaint() {
   } else {
     DCHECK(result == PP_OK);  // Catch all other errors in debug mode.
   }
-
-  in_paint_ = false;
-  first_paint_ = false;
-
-  if (graphics_need_to_be_bound_) {
-    instance_->BindGraphics(graphics_);
-    graphics_need_to_be_bound_ = false;
-  }
 }
 
 void PaintManager::OnFlushComplete(int32_t) {
@@ -298,6 +328,11 @@ void PaintManager::OnFlushComplete(int32_t) {
   // complete, execute them now.
   if (aggregator_.HasPendingUpdate())
     DoPaint();
+
+  // If there was another flush request while flushing we flush again.
+  if (flush_requested_) {
+    Flush();
+  }
 }
 
 void PaintManager::OnManualCallbackComplete(int32_t) {