Bug 1077515 - part 6 - Create a new nsISelectionController::PhysicalMove command. r=roc

dom/base/nsISelectionController.idl

@@ -16,7 +16,7 @@ interface nsIDOMNode;
 interface nsISelection;
 interface nsISelectionDisplay;
 
-[scriptable, uuid(b1ff7faa-8097-431d-b7f1-b0615e3cd596)]
+[scriptable, uuid(7835DE46-DB36-4BB7-8684-1049A0C13049)]
 interface nsISelectionController : nsISelectionDisplay
 {
    const short SELECTION_NONE=0;
@@ -143,6 +143,26 @@ interface nsISelectionController : nsISelectionDisplay
    */
     void characterMove(in boolean forward, in boolean extend);
 
+   /** PhysicalMove will move the selection one "unit" in a given direction
+   *  within the document.
+   *  this will also have the effect of collapsing the selection if the aExtend = PR_FALSE
+   *  the "point" of selection that is extended is considered the "focus" point. 
+   *  or the last point adjusted by the selection.
+   *  @param aDirection 
+   *  @param aAmount    character/line; word/lineBoundary
+   *  @param aExtend    should it collapse the selection of extend it?
+   */
+    void physicalMove(in short direction, in short amount, in boolean extend);
+
+   /**
+    * nsFrameSelection::PhysicalMove depends on the ordering of these values;
+    * do not change without checking there!
+    */
+   const short MOVE_LEFT = 0;
+   const short MOVE_RIGHT = 1;
+   const short MOVE_UP = 2;
+   const short MOVE_DOWN = 3;
+
    /**
     * CharacterExtendForDelete will extend the selection one character cell
     * forward in the document.

dom/html/nsTextEditorState.cpp

@@ -227,6 +227,7 @@ public:
   NS_IMETHOD GetCaretEnabled(bool *_retval);
   NS_IMETHOD GetCaretVisible(bool *_retval);
   NS_IMETHOD SetCaretVisibilityDuringSelection(bool aVisibility);
+  NS_IMETHOD PhysicalMove(int16_t aDirection, int16_t aAmount, bool aExtend) MOZ_OVERRIDE;
   NS_IMETHOD CharacterMove(bool aForward, bool aExtend);
   NS_IMETHOD CharacterExtendForDelete();
   NS_IMETHOD CharacterExtendForBackspace();
@@ -445,6 +446,15 @@ nsTextInputSelectionImpl::SetCaretVisibilityDuringSelection(bool aVisibility)
   return NS_ERROR_FAILURE;
 }
 
+NS_IMETHODIMP
+nsTextInputSelectionImpl::PhysicalMove(int16_t aDirection, int16_t aAmount,
+                                       bool aExtend)
+{
+  if (mFrameSelection)
+    return mFrameSelection->PhysicalMove(aDirection, aAmount, aExtend);
+  return NS_ERROR_NULL_POINTER;
+}
+
 NS_IMETHODIMP
 nsTextInputSelectionImpl::CharacterMove(bool aForward, bool aExtend)
 {

layout/base/nsPresShell.cpp

@@ -2303,6 +2303,12 @@ NS_IMETHODIMP PresShell::GetSelectionFlags(int16_t *aOutEnable)
 
 //implementation of nsISelectionController
 
+NS_IMETHODIMP
+PresShell::PhysicalMove(int16_t aDirection, int16_t aAmount, bool aExtend)
+{
+  return mSelection->PhysicalMove(aDirection, aAmount, aExtend);
+}
+
 NS_IMETHODIMP
 PresShell::CharacterMove(bool aForward, bool aExtend)
 {

layout/base/nsPresShell.h

@@ -249,6 +249,7 @@ public:
 
   // nsISelectionController
 
+  NS_IMETHOD PhysicalMove(int16_t aDirection, int16_t aAmount, bool aExtend) MOZ_OVERRIDE;
   NS_IMETHOD CharacterMove(bool aForward, bool aExtend) MOZ_OVERRIDE;
   NS_IMETHOD CharacterExtendForDelete() MOZ_OVERRIDE;
   NS_IMETHOD CharacterExtendForBackspace() MOZ_OVERRIDE;

layout/generic/nsFrameSelection.h

@@ -415,6 +415,16 @@ public:
    */
   virtual void UndefineCaretBidiLevel();
 
+  /** PhysicalMove will generally be called from the nsiselectioncontroller implementations.
+   *  the effect being the selection will move one unit 'aAmount' in the
+   *  given aDirection.
+   * @param aDirection  the direction to move the selection
+   * @param aAmount     amount of movement (char/line; word/page; eol/doc)
+   * @param aExtend     continue selection
+   */
+  /*unsafe*/
+  nsresult PhysicalMove(int16_t aDirection, int16_t aAmount, bool aExtend);
+
   /** CharacterMove will generally be called from the nsiselectioncontroller implementations.
    *  the effect being the selection will move one character left or right.
    * @param aForward move forward in document.

layout/generic/nsSelection.cpp

@@ -1897,6 +1897,96 @@ nsFrameSelection::CommonPageMove(bool aForward,
               offsets.offset, aExtend, false, CARET_ASSOCIATE_AFTER);
 }
 
+nsresult
+nsFrameSelection::PhysicalMove(int16_t aDirection, int16_t aAmount,
+                               bool aExtend)
+{
+  NS_ENSURE_STATE(mShell);
+  // Flush out layout, since we need it to be up to date to do caret
+  // positioning.
+  mShell->FlushPendingNotifications(Flush_Layout);
+
+  if (!mShell) {
+    return NS_OK;
+  }
+
+  // Check that parameters are safe
+  if (aDirection < 0 || aDirection > 3 || aAmount < 0 || aAmount > 1) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsPresContext *context = mShell->GetPresContext();
+  if (!context) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int8_t index = GetIndexFromSelectionType(nsISelectionController::SELECTION_NORMAL);
+  nsRefPtr<Selection> sel = mDomSelections[index];
+  if (!sel) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  // Map the abstract movement amounts (0-1) to direction-specific
+  // selection units.
+  static const nsSelectionAmount inlineAmount[] =
+    { eSelectCluster, eSelectWord };
+  static const nsSelectionAmount blockPrevAmount[] =
+    { eSelectLine, eSelectBeginLine };
+  static const nsSelectionAmount blockNextAmount[] =
+    { eSelectLine, eSelectEndLine };
+
+  struct PhysicalToLogicalMapping {
+    nsDirection direction;
+    const nsSelectionAmount *amounts;
+  };
+  static const PhysicalToLogicalMapping verticalLR[4] = {
+    { eDirPrevious, blockPrevAmount },  // left
+    { eDirNext, blockNextAmount },      // right
+    { eDirPrevious, inlineAmount }, // up
+    { eDirNext, inlineAmount }      // down
+  };
+  static const PhysicalToLogicalMapping verticalRL[4] = {
+    { eDirNext, blockNextAmount },
+    { eDirPrevious, blockPrevAmount },
+    { eDirPrevious, inlineAmount },
+    { eDirNext, inlineAmount }
+  };
+  static const PhysicalToLogicalMapping horizontal[4] = {
+    { eDirPrevious, inlineAmount },
+    { eDirNext, inlineAmount },
+    { eDirPrevious, blockPrevAmount },
+    { eDirNext, blockNextAmount }
+  };
+
+  WritingMode wm;
+  nsIFrame *frame = nullptr;
+  int32_t offsetused = 0;
+  if (NS_SUCCEEDED(sel->GetPrimaryFrameForFocusNode(&frame, &offsetused,
+                                                    true))) {
+    if (frame) {
+      wm = frame->GetWritingMode();
+    }
+  }
+
+  const PhysicalToLogicalMapping& mapping =
+    wm.IsVertical()
+      ? wm.IsVerticalLR() ? verticalLR[aDirection] : verticalRL[aDirection]
+      : horizontal[aDirection];
+
+  nsresult rv = MoveCaret(mapping.direction, aExtend, mapping.amounts[aAmount],
+                          eVisual);
+  if (NS_FAILED(rv)) {
+    // If we tried to do a line move, but couldn't move in the given direction,
+    // then we'll "promote" this to a line-edge move instead.
+    if (mapping.amounts[aAmount] == eSelectLine) {
+      rv = MoveCaret(mapping.direction, aExtend, mapping.amounts[aAmount + 1],
+                     eVisual);
+    }
+  }
+
+  return rv;
+}
+
 nsresult
 nsFrameSelection::CharacterMove(bool aForward, bool aExtend)
 {