Migrate OnGeometryChanged(), SetZoom(), kMinZoom to PdfViewPluginBase.

In OutOfProcessInstance, private methods OnGeometryChanged() and
SetZoom() and the local variable `kMinZoom` will be used for drawing
graphics by PdfViewWebPlugin in the future. This CL migrates these
methods to PdfViewPluginBase as protected methods and moves the
definition of `kMinZoom` to PdfViewPluginBase, so that they can be
shared by both plugin instances.

Bug: 1140629
Change-Id: I4016bf05871c2112b653ce0e043261c94580c534
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2602518
Commit-Queue: Hui Yingst <nigi@chromium.org>
Reviewed-by: K. Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839461}

pdf/out_of_process_instance.cc

@@ -261,8 +261,6 @@ constexpr int kInvalidPDFIndex = -2;
 constexpr base::TimeDelta kAccessibilityPageDelay =
     base::TimeDelta::FromMilliseconds(100);
 
-constexpr double kMinZoom = 0.01;
-
 constexpr char kPPPPdfInterface[] = PPP_PDF_INTERFACE_1;
 
 PP_Var GetLinkAtPosition(PP_Instance instance, PP_Point point) {
@@ -2228,12 +2226,6 @@ std::unique_ptr<UrlLoader> OutOfProcessInstance::CreateUrlLoaderInternal() {
   return loader;
 }
 
-void OutOfProcessInstance::SetZoom(double scale) {
-  double old_zoom = zoom();
-  set_zoom(scale);
-  OnGeometryChanged(old_zoom, device_scale());
-}
-
 void OutOfProcessInstance::AppendBlankPrintPreviewPages() {
   engine()->AppendBlankPages(print_preview_page_count_);
   LoadNextPreviewPage();

pdf/out_of_process_instance.h

@@ -187,6 +187,7 @@ class OutOfProcessInstance : public PdfViewPluginBase,
   void DoPaint(const std::vector<gfx::Rect>& paint_rects,
                std::vector<PaintReadyRect>* ready,
                std::vector<gfx::Rect>* pending) override;
+  void OnGeometryChanged(double old_zoom, float old_device_scale) override;
 
  private:
   // Message handlers.
@@ -210,10 +211,6 @@ class OutOfProcessInstance : public PdfViewPluginBase,
 
   void ResetRecentlySentFindUpdate(int32_t);
 
-  // Called whenever the plugin geometry changes to update the location of the
-  // background parts, and notifies the pdf engine.
-  void OnGeometryChanged(double old_zoom, float old_device_scale);
-
   // Figures out the location of any background rectangles (i.e. those that
   // aren't painted by the PDF engine).
   void CalculateBackgroundParts();
@@ -267,9 +264,6 @@ class OutOfProcessInstance : public PdfViewPluginBase,
     kEdited = 2,
   };
 
-  // Set new zoom scale.
-  void SetZoom(double scale);
-
   // Reduces the document to 1 page and appends |print_preview_page_count_| - 1
   // blank pages to the document for print preview.
   void AppendBlankPrintPreviewPages();

pdf/pdf_view_plugin_base.cc

@@ -17,6 +17,9 @@
 
 namespace chrome_pdf {
 
+// static
+constexpr double PdfViewPluginBase::kMinZoom;
+
 PdfViewPluginBase::PdfViewPluginBase() = default;
 
 PdfViewPluginBase::~PdfViewPluginBase() = default;
@@ -56,4 +59,10 @@ void PdfViewPluginBase::LoadUrl(const std::string& url, bool is_print_preview) {
                      GetWeakPtr(), std::move(loader)));
 }
 
+void PdfViewPluginBase::SetZoom(double scale) {
+  double old_zoom = zoom_;
+  zoom_ = scale;
+  OnGeometryChanged(old_zoom, device_scale_);
+}
+
 }  // namespace chrome_pdf

pdf/pdf_view_plugin_base.h

@@ -38,6 +38,9 @@ class PdfViewPluginBase : public PDFEngine::Client,
                std::vector<gfx::Rect>* pending) override;
 
  protected:
+  // The mininum zoom level allowed.
+  static constexpr double kMinZoom = 0.01;
+
   PdfViewPluginBase();
   ~PdfViewPluginBase() override;
 
@@ -76,6 +79,10 @@ class PdfViewPluginBase : public PDFEngine::Client,
                        std::vector<PaintReadyRect>* ready,
                        std::vector<gfx::Rect>* pending) = 0;
 
+  // Called whenever the plugin geometry changes to update the location of the
+  // background parts, and notifies the pdf engine.
+  virtual void OnGeometryChanged(double old_zoom, float old_device_scale) = 0;
+
   void SetBackgroundColor(uint32_t background_color) {
     background_color_ = background_color;
   }
@@ -88,8 +95,10 @@ class PdfViewPluginBase : public PDFEngine::Client,
     top_toolbar_height_in_viewport_coords_ = height;
   }
 
+  // Sets the new zoom scale.
+  void SetZoom(double scale);
+
   double zoom() const { return zoom_; }
-  void set_zoom(double zoom) { zoom_ = zoom; }
 
   float device_scale() const { return device_scale_; }
   void set_device_scale(float device_scale) { device_scale_ = device_scale; }

pdf/pdf_view_web_plugin.cc

@@ -397,4 +397,9 @@ void PdfViewWebPlugin::DoPaint(const std::vector<gfx::Rect>& paint_rects,
   NOTIMPLEMENTED_LOG_ONCE();
 }
 
+// TODO(https://crbug.com/1099020): To be implemented as a Pepper-free version
+// of `OutOfProcessInstance::OnGeometryChanged()`
+void PdfViewWebPlugin::OnGeometryChanged(double old_zoom,
+                                         float old_device_scale) {}
+
 }  // namespace chrome_pdf

pdf/pdf_view_web_plugin.h

@@ -130,6 +130,7 @@ class PdfViewWebPlugin final : public PdfViewPluginBase,
   void DoPaint(const std::vector<gfx::Rect>& paint_rects,
                std::vector<PaintReadyRect>* ready,
                std::vector<gfx::Rect>* pending) override;
+  void OnGeometryChanged(double old_zoom, float old_device_scale) override;
 
  private:
   // Call `Destroy()` instead.