[InputEvent] Support |deleteByDrag|, |insertFromDrop| and fire in sequential order

third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp

Index: third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp b/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
index ff59f692da5e64999f8a10ff005688fa94c4e27b..8954d3ad619a9ef779fe4cb51a60c4cc83b31a72 100644
--- a/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/DeleteSelectionCommand.cpp
@@ -33,6 +33,7 @@
 #include "core/editing/EditingBoundary.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/Editor.h"
+#include "core/editing/RelocatablePosition.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLBRElement.h"
@@ -63,7 +64,7 @@ static bool isTableRowEmpty(Node* row)
     return true;
 }
 
-DeleteSelectionCommand::DeleteSelectionCommand(Document& document, bool smartDelete, bool mergeBlocksAfterDelete, bool expandForSpecialElements, bool sanitizeMarkup, InputEvent::InputType inputType)
+DeleteSelectionCommand::DeleteSelectionCommand(Document& document, bool smartDelete, bool mergeBlocksAfterDelete, bool expandForSpecialElements, bool sanitizeMarkup, InputEvent::InputType inputType, const Position& referenceMovePosition)
     : CompositeEditCommand(document)
     , m_hasSelectionToDelete(false)
     , m_smartDelete(smartDelete)
@@ -74,6 +75,7 @@ DeleteSelectionCommand::DeleteSelectionCommand(Document& document, bool smartDel
     , m_startsAtEmptyLine(false)
     , m_sanitizeMarkup(sanitizeMarkup)
     , m_inputType(inputType)
+    , m_referenceMovePosition(referenceMovePosition)
     , m_startBlock(nullptr)
     , m_endBlock(nullptr)
     , m_typingStyle(nullptr)
@@ -808,6 +810,7 @@ void DeleteSelectionCommand::clearTransientState()
     m_endingPosition = Position();
     m_leadingWhitespace = Position();
     m_trailingWhitespace = Position();
+    m_referenceMovePosition = Position();
 }
 
 // This method removes div elements with no attributes that have only one child or no children at all.
@@ -841,6 +844,8 @@ void DeleteSelectionCommand::doApply(EditingState* editingState)
     if (!m_selectionToDelete.isNonOrphanedRange() || !m_selectionToDelete.isContentEditable())
         return;
 
+    RelocatablePosition relocatableReferencePosition(m_referenceMovePosition);

[yosin_UTC9, 2016/10/03 09:19:03]

Good usage!

[chongz, 2016/10/04 02:18:39]

Thanks!

+
     // save this to later make the selection with
     TextAffinity affinity = m_selectionToDelete.affinity();
 
@@ -931,6 +936,23 @@ void DeleteSelectionCommand::doApply(EditingState* editingState)
     calculateTypingStyleAfterDelete();
 
     setEndingSelection(VisibleSelection(m_endingPosition, affinity, endingSelection().isDirectional()));
+
+    // This deletion command is part or a move operation.
+    if (relocatableReferencePosition.position().isNotNull()) {

[yosin_UTC9, 2016/10/03 09:19:03]

Could you use early-return style?

if (relocatableReferencePosition.position().isNull()) {
  clearTransientState();
  return;
}

...

It is OK to appear |clearTransientState()| twice.

[chongz, 2016/10/04 02:18:39]

Done.

+        m_referenceMovePosition = relocatableReferencePosition.position();
+        // If the node for the destination has been removed as a result of the deletion,
+        // set the destination to the ending point after the deletion.
+        // Fixes: <rdar://problem/3910425> REGRESSION (Mail): Crash in ReplaceSelectionCommand;
+        //        selection is empty, leading to null deref
+        if (!m_referenceMovePosition.isConnected())
+            m_referenceMovePosition = endingSelection().start();
+
+        // Move selection shouldn't left empty <li> block.
+        cleanupAfterDeletion(editingState, createVisiblePositionDeprecated(m_referenceMovePosition));
+        if (editingState->isAborted())
+            return;
+    }
+
     clearTransientState();
 }
 
@@ -960,6 +982,7 @@ DEFINE_TRACE(DeleteSelectionCommand)
     visitor->trace(m_endingPosition);
     visitor->trace(m_leadingWhitespace);
     visitor->trace(m_trailingWhitespace);
+    visitor->trace(m_referenceMovePosition);
     visitor->trace(m_startBlock);
     visitor->trace(m_endBlock);
     visitor->trace(m_typingStyle);