Improved Pinch-Zoom for PDF.

pdf/out_of_process_instance.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PDF_OUT_OF_PROCESS_INSTANCE_H_
 #define PDF_OUT_OF_PROCESS_INSTANCE_H_
 
 #include <stdint.h>
 #include <string.h>
 
@@ skipping 217 matching lines @@
   pp::Size plugin_size_;
   // Size, in DIPs, of plugin rectangle.
   pp::Size plugin_dip_size_;
   // Remaining area, in pixels, to render the pdf in after accounting for
   // horizontal centering.
   pp::Rect available_area_;
   // Size of entire document in pixels (i.e. if each page is 800 pixels high and
   // there are 10 pages, the height will be 8000).
   pp::Size document_size_;
 
-  double zoom_;  // Current zoom factor.
+  // Enumeration of pinch states.
+  // This should match PinchPhase enum in
+  // chrome/browser/resources/pdf/viewport.js
+  enum PinchPhase {
+      PINCH_NONE = 0,

[Lei Zhang, 2016/10/27 23:04:33]

nit: 2 space indent.

[Kevin McNee - google account, 2016/10/28 19:19:37]

Done.

+      PINCH_START = 1,
+      PINCH_UPDATE_ZOOM_OUT = 2,
+      PINCH_UPDATE_ZOOM_IN = 3,
+      PINCH_END = 4
+  };
 
-  float device_scale_;  // Current device scale factor.
+  // Current zoom factor.
+  double zoom_;
+  double old_zoom_;
+  double initial_zoom_delta_;
+  // True if we request a new bitmap rendering.
+  bool needs_reraster_;
+  // Scroll at the beginning of zooming.
+  pp::FloatPoint last_current_scroll_;
+  // True if last bitmap was smaller than screen.
+  bool was_smaller_;
+  // Current device scale factor.
+  float device_scale_;
   // True if the plugin is full-page.
   bool full_;
 
   PaintManager paint_manager_;
 
   struct BackgroundPart {
     pp::Rect location;
     uint32_t color;
   };
   std::vector<BackgroundPart> background_parts_;
@@ skipping 111 matching lines @@
     ACCESSIBILITY_STATE_PENDING,  // Enabled but waiting for doc to load.
     ACCESSIBILITY_STATE_LOADED
   } accessibility_state_;
 
   DISALLOW_COPY_AND_ASSIGN(OutOfProcessInstance);
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_OUT_OF_PROCESS_INSTANCE_H_