Pan around PDF with middle mouse drag.

Bug: 234933
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I4a42336006cf553bf52d30be4656f953d8341323
Reviewed-on: https://chromium-review.googlesource.com/974447Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546017}

chrome/browser/resources/pdf/pdf.js

@@ -699,12 +699,10 @@ PDFViewer.prototype = {
         this.sendDocumentLoadedMessage_();
         break;
       case 'setScrollPosition':
-        var position = this.viewport_.position;
-        if (message.data.x !== undefined)
-          position.x = message.data.x;
-        if (message.data.y !== undefined)
-          position.y = message.data.y;
-        this.viewport_.position = position;
+        this.viewport_.scrollTo(/** @type {!PartialPoint} */ (message.data));
+        break;
+      case 'scrollBy':
+        this.viewport_.scrollBy(/** @type {!Point} */ (message.data));
         break;
       case 'cancelStreamUrl':
         chrome.mimeHandlerPrivate.abortStream();

chrome/browser/resources/pdf/viewport.js

@@ -2,6 +2,22 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+/**
+ * @typedef {{
+ *   x: number,
+ *   y: number
+ * }}
+ */
+let Point;
+
+/**
+ * @typedef {{
+ *   x: number | undefined,
+ *   y: number | undefined
+ * }}
+ */
+let PartialPoint;
+
 /**
  * Returns the height of the intersection of two rectangles.
  * @param {Object} rect1 the first rect
@@ -254,7 +270,7 @@ Viewport.prototype = {
 
   /**
    * Scroll the viewport to the specified position.
-   * @type {Object} position the position to scroll to.
+   * @type {Object} position The position to scroll to.
    */
   set position(position) {
     this.window_.scrollTo(position.x, position.y + this.topToolbarHeight_);
@@ -906,5 +922,38 @@ Viewport.prototype = {
     return (
         this.fittingType_ == FittingType.FIT_TO_PAGE ||
         this.fittingType_ == FittingType.FIT_TO_HEIGHT);
+  },
+
+  /**
+   * Scroll the viewport to the specified position.
+   *
+   * @param {!PartialPoint} point The position to which to move the viewport.
+   */
+  scrollTo: function(point) {
+    let changed = false;
+    const newPosition = this.position;
+    if (point.x !== undefined && point.x != newPosition.x) {
+      newPosition.x = point.x;
+      changed = true;
+    }
+    if (point.y !== undefined && point.y != newPosition.y) {
+      newPosition.y = point.y;
+      changed = true;
+    }
+
+    if (changed)
+      this.position = newPosition;
+  },
+
+  /**
+   * Scroll the viewport by the specified delta.
+   *
+   * @param {!Point} delta The delta by which to move the viewport.
+   */
+  scrollBy: function(delta) {
+    const newPosition = this.position;
+    newPosition.x += delta.x;
+    newPosition.y += delta.y;
+    this.scrollTo(newPosition);
   }
 };

chrome/test/data/pdf/viewport_test.js

@@ -605,6 +605,110 @@ var tests = [
     chrome.test.succeed();
   },
 
+  function testScrollTo() {
+    var mockWindow = new MockWindow(100, 100);
+    var mockSizer = new MockSizer();
+    var mockCallback = new MockViewportChangedCallback();
+    var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
+                                function() {}, function() {}, function() {},
+                                0, 1, 0);
+    var documentDimensions = new MockDocumentDimensions();
+
+    documentDimensions.addPage(200, 200);
+    viewport.setDocumentDimensions(documentDimensions);
+    viewport.setZoom(1);
+
+    chrome.test.assertEq(0, viewport.position.x);
+    chrome.test.assertEq(0, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollTo({x: 0, y: 0});
+    chrome.test.assertFalse(mockCallback.wasCalled);
+    chrome.test.assertEq(0, viewport.position.x);
+    chrome.test.assertEq(0, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollTo({x: 10, y: 20});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(10, viewport.position.x);
+    chrome.test.assertEq(20, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollTo({y: 30});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(10, viewport.position.x);
+    chrome.test.assertEq(30, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollTo({y: 30});
+    chrome.test.assertFalse(mockCallback.wasCalled);
+    chrome.test.assertEq(10, viewport.position.x);
+    chrome.test.assertEq(30, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollTo({x: 40});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(40, viewport.position.x);
+    chrome.test.assertEq(30, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollTo({});
+    chrome.test.assertFalse(mockCallback.wasCalled);
+    chrome.test.assertEq(40, viewport.position.x);
+    chrome.test.assertEq(30, viewport.position.y);
+
+    chrome.test.succeed();
+  },
+
+  function testScrollBy() {
+    var mockWindow = new MockWindow(100, 100);
+    var mockSizer = new MockSizer();
+    var mockCallback = new MockViewportChangedCallback();
+    var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
+                                function() {}, function() {}, function() {},
+                                0, 1, 0);
+    var documentDimensions = new MockDocumentDimensions();
+
+    documentDimensions.addPage(200, 200);
+    viewport.setDocumentDimensions(documentDimensions);
+    viewport.setZoom(1);
+
+    chrome.test.assertEq(0, viewport.position.x);
+    chrome.test.assertEq(0, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollBy({x: 10, y: 20});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(10, viewport.position.x);
+    chrome.test.assertEq(20, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollBy({x: 10, y: 20});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(20, viewport.position.x);
+    chrome.test.assertEq(40, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollBy({x: -5, y: 0});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(15, viewport.position.x);
+    chrome.test.assertEq(40, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollBy({x: 0, y: 60});
+    chrome.test.assertTrue(mockCallback.wasCalled);
+    chrome.test.assertEq(15, viewport.position.x);
+    chrome.test.assertEq(100, viewport.position.y);
+
+    mockCallback.reset();
+    viewport.scrollBy({x: 0, y: 0});
+    chrome.test.assertFalse(mockCallback.wasCalled);
+    chrome.test.assertEq(15, viewport.position.x);
+    chrome.test.assertEq(100, viewport.position.y);
+
+    chrome.test.succeed();
+  },
+
   function testGetPageScreenRect() {
     var mockWindow = new MockWindow(100, 100);
     var mockSizer = new MockSizer();

pdf/out_of_process_instance.cc

@@ -112,6 +112,8 @@ const char kJSPreviewPageIndex[] = "index";
 const char kJSSetScrollPositionType[] = "setScrollPosition";
 const char kJSPositionX[] = "x";
 const char kJSPositionY[] = "y";
+// Scroll by (Plugin -> Page)
+const char kJSScrollByType[] = "scrollBy";
 // Cancel the stream URL request (Plugin -> Page)
 const char kJSCancelStreamUrlType[] = "cancelStreamUrl";
 // Navigate to the given URL (Plugin -> Page)
@@ -1242,6 +1244,14 @@ void OutOfProcessInstance::ScrollToY(int y_in_screen_coords,
   PostMessage(position);
 }
 
+void OutOfProcessInstance::ScrollBy(const pp::Point& point) {
+  pp::VarDictionary position;
+  position.Set(kType, kJSScrollByType);
+  position.Set(kJSPositionX, pp::Var(point.x() / device_scale_));
+  position.Set(kJSPositionY, pp::Var(point.y() / device_scale_));
+  PostMessage(position);
+}
+
 void OutOfProcessInstance::ScrollToPage(int page) {
   if (engine_->GetNumberOfPages() == 0)
     return;

pdf/out_of_process_instance.h

@@ -101,6 +101,7 @@ class OutOfProcessInstance : public pp::Instance,
   void DidScroll(const pp::Point& point) override;
   void ScrollToX(int x_in_screen_coords) override;
   void ScrollToY(int y_in_screen_coords, bool compensate_for_toolbar) override;
+  void ScrollBy(const pp::Point& point) override;
   void ScrollToPage(int page) override;
   void NavigateTo(const std::string& url,
                   WindowOpenDisposition disposition) override;

pdf/pdf_engine.h

@@ -146,6 +146,9 @@ class PDFEngine {
     virtual void ScrollToY(int y_in_screen_coords,
                            bool compensate_for_toolbar) = 0;
 
+    // Scroll by a given delta relative to the current position.
+    virtual void ScrollBy(const pp::Point& point) = 0;
+
     // Scroll to zero-based |page|.
     virtual void ScrollToPage(int page) = 0;
 

pdf/pdfium/pdfium_engine.cc

@@ -758,6 +758,7 @@ PDFiumEngine::PDFiumEngine(PDFEngine::Client* client)
       in_form_text_area_(false),
       editable_form_text_area_(false),
       mouse_left_button_down_(false),
+      mouse_middle_button_down_(false),
       permissions_(0),
       permissions_handler_revision_(-1),
       fpdf_availability_(nullptr),
@@ -1448,6 +1449,9 @@ bool PDFiumEngine::HandleEvent(const pp::InputEvent& event) {
     case PP_INPUTEVENT_TYPE_MOUSEMOVE:
       rv = OnMouseMove(pp::MouseInputEvent(event));
       break;
+    case PP_INPUTEVENT_TYPE_MOUSEENTER:
+      OnMouseEnter(pp::MouseInputEvent(event));
+      break;
     case PP_INPUTEVENT_TYPE_KEYDOWN:
       rv = OnKeyDown(pp::KeyboardInputEvent(event));
       break;
@@ -1947,6 +1951,8 @@ bool PDFiumEngine::OnLeftMouseDown(const pp::MouseInputEvent& event) {
 
 bool PDFiumEngine::OnMiddleMouseDown(const pp::MouseInputEvent& event) {
   SetMouseLeftButtonDown(false);
+  mouse_middle_button_down_ = true;
+  mouse_middle_button_last_position_ = event.GetPosition();
 
   SelectionChangeInvalidator selection_invalidator(this);
   selection_.clear();
@@ -2047,6 +2053,8 @@ bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
 
   if (event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT)
     SetMouseLeftButtonDown(false);
+  else if (event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_MIDDLE)
+    mouse_middle_button_down_ = false;
 
   int page_index = -1;
   int char_index = -1;
@@ -2121,48 +2129,7 @@ bool PDFiumEngine::OnMouseMove(const pp::MouseInputEvent& event) {
     mouse_down_state_.Reset();
 
   if (!selecting_) {
-    PP_CursorType_Dev cursor;
-    switch (area) {
-      case PDFiumPage::TEXT_AREA:
-        cursor = PP_CURSORTYPE_IBEAM;
-        break;
-      case PDFiumPage::WEBLINK_AREA:
-      case PDFiumPage::DOCLINK_AREA:
-        cursor = PP_CURSORTYPE_HAND;
-        break;
-      case PDFiumPage::NONSELECTABLE_AREA:
-      case PDFiumPage::FORM_TEXT_AREA:
-      default:
-        switch (form_type) {
-          case FPDF_FORMFIELD_PUSHBUTTON:
-          case FPDF_FORMFIELD_CHECKBOX:
-          case FPDF_FORMFIELD_RADIOBUTTON:
-          case FPDF_FORMFIELD_COMBOBOX:
-          case FPDF_FORMFIELD_LISTBOX:
-            cursor = PP_CURSORTYPE_HAND;
-            break;
-          case FPDF_FORMFIELD_TEXTFIELD:
-            cursor = PP_CURSORTYPE_IBEAM;
-            break;
-#if defined(PDF_ENABLE_XFA)
-          case FPDF_FORMFIELD_XFA_CHECKBOX:
-          case FPDF_FORMFIELD_XFA_COMBOBOX:
-          case FPDF_FORMFIELD_XFA_IMAGEFIELD:
-          case FPDF_FORMFIELD_XFA_LISTBOX:
-          case FPDF_FORMFIELD_XFA_PUSHBUTTON:
-          case FPDF_FORMFIELD_XFA_SIGNATURE:
-            cursor = PP_CURSORTYPE_HAND;
-            break;
-          case FPDF_FORMFIELD_XFA_TEXTFIELD:
-            cursor = PP_CURSORTYPE_IBEAM;
-            break;
-#endif
-          default:
-            cursor = PP_CURSORTYPE_POINTER;
-            break;
-        }
-        break;
-    }
+    client_->UpdateCursor(DetermineCursorType(area, form_type));
 
     if (page_index != -1) {
       double page_x;
@@ -2171,7 +2138,6 @@ bool PDFiumEngine::OnMouseMove(const pp::MouseInputEvent& event) {
       FORM_OnMouseMove(form_, pages_[page_index]->GetPage(), 0, page_x, page_y);
     }
 
-    client_->UpdateCursor(cursor);
     std::string url = GetLinkAtPosition(event.GetPosition());
     if (url != link_under_cursor_) {
       link_under_cursor_ = url;
@@ -2185,6 +2151,19 @@ bool PDFiumEngine::OnMouseMove(const pp::MouseInputEvent& event) {
       SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
     }
 
+    if (mouse_middle_button_down_) {
+      // Subtract (origin - destination) so delta is already the delta for
+      // moving the page, rather than the delta the mouse moved.
+      // GetMovement() does not work here, as small mouse movements are
+      // considered zero.
+      pp::Point page_position_delta =
+          mouse_middle_button_last_position_ - event.GetPosition();
+      if (page_position_delta.x() != 0 || page_position_delta.y() != 0) {
+        client_->ScrollBy(page_position_delta);
+        mouse_middle_button_last_position_ = event.GetPosition();
+      }
+    }
+
     // No need to swallow the event, since this might interfere with the
     // scrollbars if the user is dragging them.
     return false;
@@ -2199,6 +2178,60 @@ bool PDFiumEngine::OnMouseMove(const pp::MouseInputEvent& event) {
   return ExtendSelection(page_index, char_index);
 }
 
+PP_CursorType_Dev PDFiumEngine::DetermineCursorType(PDFiumPage::Area area,
+                                                    int form_type) const {
+  if (mouse_middle_button_down_) {
+    return PP_CURSORTYPE_HAND;
+  }
+
+  switch (area) {
+    case PDFiumPage::TEXT_AREA:
+      return PP_CURSORTYPE_IBEAM;
+    case PDFiumPage::WEBLINK_AREA:
+    case PDFiumPage::DOCLINK_AREA:
+      return PP_CURSORTYPE_HAND;
+    case PDFiumPage::NONSELECTABLE_AREA:
+    case PDFiumPage::FORM_TEXT_AREA:
+    default:
+      switch (form_type) {
+        case FPDF_FORMFIELD_PUSHBUTTON:
+        case FPDF_FORMFIELD_CHECKBOX:
+        case FPDF_FORMFIELD_RADIOBUTTON:
+        case FPDF_FORMFIELD_COMBOBOX:
+        case FPDF_FORMFIELD_LISTBOX:
+          return PP_CURSORTYPE_HAND;
+        case FPDF_FORMFIELD_TEXTFIELD:
+          return PP_CURSORTYPE_IBEAM;
+#if defined(PDF_ENABLE_XFA)
+        case FPDF_FORMFIELD_XFA_CHECKBOX:
+        case FPDF_FORMFIELD_XFA_COMBOBOX:
+        case FPDF_FORMFIELD_XFA_IMAGEFIELD:
+        case FPDF_FORMFIELD_XFA_LISTBOX:
+        case FPDF_FORMFIELD_XFA_PUSHBUTTON:
+        case FPDF_FORMFIELD_XFA_SIGNATURE:
+          return PP_CURSORTYPE_HAND;
+        case FPDF_FORMFIELD_XFA_TEXTFIELD:
+          return PP_CURSORTYPE_IBEAM;
+#endif
+        default:
+          return PP_CURSORTYPE_POINTER;
+      }
+  }
+}
+
+void PDFiumEngine::OnMouseEnter(const pp::MouseInputEvent& event) {
+  if (event.GetModifiers() & PP_INPUTEVENT_MODIFIER_MIDDLEBUTTONDOWN) {
+    if (!mouse_middle_button_down_) {
+      mouse_middle_button_down_ = true;
+      mouse_middle_button_last_position_ = event.GetPosition();
+    }
+  } else {
+    if (mouse_middle_button_down_) {
+      mouse_middle_button_down_ = false;
+    }
+  }
+}
+
 bool PDFiumEngine::ExtendSelection(int page_index, int char_index) {
   // Check if the user has decreased their selection area and we need to remove
   // pages from |selection_|.

pdf/pdfium/pdfium_engine.h

@@ -295,10 +295,15 @@ class PDFiumEngine : public PDFEngine,
   bool OnMouseDown(const pp::MouseInputEvent& event);
   bool OnMouseUp(const pp::MouseInputEvent& event);
   bool OnMouseMove(const pp::MouseInputEvent& event);
+  void OnMouseEnter(const pp::MouseInputEvent& event);
   bool OnKeyDown(const pp::KeyboardInputEvent& event);
   bool OnKeyUp(const pp::KeyboardInputEvent& event);
   bool OnChar(const pp::KeyboardInputEvent& event);
 
+  // Decide what cursor should be displayed.
+  PP_CursorType_Dev DetermineCursorType(PDFiumPage::Area area,
+                                        int form_type) const;
+
   bool ExtendSelection(int page_index, int char_index);
 
   FPDF_DOCUMENT CreateSinglePageRasterPdf(
@@ -699,6 +704,12 @@ class PDFiumEngine : public PDFEngine,
   // True if left mouse button is currently being held down.
   bool mouse_left_button_down_;
 
+  // True if middle mouse button is currently being held down.
+  bool mouse_middle_button_down_;
+
+  // Last known position while performing middle mouse button pan.
+  pp::Point mouse_middle_button_last_position_;
+
   // The current text used for searching.
   std::string current_find_text_;
   // The results found.

pdf/preview_mode_client.cc

@@ -31,6 +31,10 @@ void PreviewModeClient::ScrollToY(int y_in_screen_coords,
   NOTREACHED();
 }
 
+void PreviewModeClient::ScrollBy(const pp::Point& point) {
+  NOTREACHED();
+}
+
 void PreviewModeClient::ScrollToPage(int page) {
   NOTREACHED();
 }

pdf/preview_mode_client.h

@@ -32,6 +32,7 @@ class PreviewModeClient : public PDFEngine::Client {
   void DidScroll(const pp::Point& point) override;
   void ScrollToX(int x_in_screen_coords) override;
   void ScrollToY(int y_in_screen_coords, bool compensate_for_toolbar) override;
+  void ScrollBy(const pp::Point& point) override;
   void ScrollToPage(int page) override;
   void NavigateTo(const std::string& url,
                   WindowOpenDisposition disposition) override;