[PDF Ink Signatures] Plumb page size in points for PdfInkModule

Add plumbing for getting a PDF page's size in points through to
PdfInkModuleClient.  This makes that size available for PdfInkModule,
to use for an upcoming update to the Ink strokes rendering transform.

Also define a constant for the conversion factor from pixels to points,
which while used once here can be used repeatedly in future CLs.

Bug: 380038343
Change-Id: Idfb2c350a00e87644ee1099ccd6b33731803d0c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6311049
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Alan Screen <awscreen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1426612}

pdf/pdf_ink_module_client.h

@@ -53,6 +53,10 @@ class PdfInkModuleClient {
   // non-negative page index returned from `VisiblePageIndexFromPoint()`.
   virtual gfx::Rect GetPageContentsRect(int page_index) = 0;
 
+  // Gets the page size in points for `page_index`.  Must be non-empty for any
+  // non-negative page index returned from `VisiblePageIndexFromPoint()`.
+  virtual gfx::SizeF GetPageSizeInPoints(int page_index) = 0;
+
   // Gets the thumbnail size for `page_index`. The size must be non-empty for
   // any valid page index.
   virtual gfx::Size GetThumbnailSize(int page_index) = 0;

pdf/pdf_ink_module_unittest.cc

@@ -30,6 +30,7 @@
 #include "pdf/test/mouse_event_builder.h"
 #include "pdf/test/pdf_ink_test_helpers.h"
 #include "pdf/ui/thumbnail.h"
+#include "printing/units.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/common/input/web_mouse_event.h"
@@ -267,6 +268,14 @@ class FakeClient : public PdfInkModuleClient {
     return gfx::ToEnclosedRect(page_layouts_[page_index]);
   }
 
+  gfx::SizeF GetPageSizeInPoints(int page_index) override {
+    CHECK_GE(page_index, 0);
+    CHECK_LT(static_cast<size_t>(page_index), page_layouts_.size());
+    gfx::SizeF page_size = page_layouts_[page_index].size();
+    page_size.Scale(printing::kUnitConversionFactorPixelsToPoints);
+    return page_size;
+  }
+
   float GetZoom() const override { return zoom_; }
 
   void Invalidate(const gfx::Rect& rect) override {

pdf/pdf_view_web_plugin.cc

@@ -291,6 +291,13 @@ class PdfViewWebPlugin::PdfInkModuleClientImpl : public PdfInkModuleClient {
     return plugin_->engine_->GetPageContentsRect(page_index);
   }
 
+  gfx::SizeF GetPageSizeInPoints(int page_index) override {
+    if (page_index < 0 || page_index >= plugin_->engine_->GetNumberOfPages()) {
+      return gfx::SizeF();
+    }
+    return plugin_->engine_->GetPageSizeInPoints(page_index).value();
+  }
+
   gfx::Size GetThumbnailSize(int page_index) override {
     return plugin_->engine_->GetThumbnailSize(page_index,
                                               plugin_->device_scale_);

pdf/pdf_view_web_plugin_unittest.cc

@@ -2622,6 +2622,8 @@ class PdfViewWebPluginInkTest : public PdfViewWebPluginTest {
         .WillByDefault([](int page_index) -> gfx::Rect {
           return gfx::Rect(/*x=*/0, /*y=*/0, /*width=*/100, /*height=*/50);
         });
+    ON_CALL(*engine_ptr_, GetPageSizeInPoints)
+        .WillByDefault(Return(gfx::SizeF(/*width=*/75.0f, /*height=*/37.5f)));
     ON_CALL(*engine_ptr_, GetThumbnailSize)
         .WillByDefault(Return(gfx::Size(50, 25)));
     ON_CALL(*engine_ptr_, IsPageVisible)
@@ -2782,6 +2784,13 @@ TEST_F(PdfViewWebPluginInkTest, UpdateCursor) {
   EXPECT_EQ(ui::mojom::CursorType::kPointer, cursor.type());
 }
 
+TEST_F(PdfViewWebPluginInkTest, GetPageSizeInPoints) {
+  SetUpWithTrivialInkStrokes();
+  EXPECT_EQ(gfx::SizeF(75.0f, 37.5f),
+            plugin_->ink_module_client_for_testing()->GetPageSizeInPoints(
+                /*page_index=*/0));
+}
+
 TEST_F(PdfViewWebPluginInkTest, GetThumbnailSize) {
   SetUpWithTrivialInkStrokes();
   EXPECT_EQ(gfx::Size(50, 25),

pdf/pdfium/pdfium_engine.h

@@ -336,7 +336,7 @@ class PDFiumEngine : public DocumentLoader::Client, public IFSDK_PAUSE {
   // Gets the size of the page in points for the page at `page_index`. Any
   // fractional portion of the size is retained in the result.  Returns
   // `std::nullopt` if the indicated page index is not available.
-  std::optional<gfx::SizeF> GetPageSizeInPoints(int page_index) const;
+  virtual std::optional<gfx::SizeF> GetPageSizeInPoints(int page_index) const;
 
   // Returns the uniform page size of the document in points. Returns
   // `std::nullopt` if the document has more than one page size.

pdf/test/test_pdfium_engine.h

@@ -88,6 +88,11 @@ class TestPDFiumEngine : public PDFiumEngine {
 
   MOCK_METHOD(gfx::Rect, GetPageScreenRect, (int), (const override));
 
+  MOCK_METHOD(std::optional<gfx::SizeF>,
+              GetPageSizeInPoints,
+              (int),
+              (const override));
+
   // Returns an empty bookmark list.
   base::Value::List GetBookmarks() override;
 

printing/units.h

@@ -31,6 +31,10 @@ constexpr int kPointsPerInch = 72;
 // http://dev.w3.org/csswg/css3-values/#the-px-unit
 constexpr int kPixelsPerInch = 96;
 
+// Factor to convert from pixels per inch to points per inch.
+inline constexpr float kUnitConversionFactorPixelsToPoints =
+    static_cast<float>(kPointsPerInch) / kPixelsPerInch;
+
 #if BUILDFLAG(IS_MAC)
 constexpr int kDefaultMacDpi = 72;
 #endif  // BUILDFLAG(IS_MAC)