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

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

 /*
  * Copyright (C) 2005 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 15 matching lines @@
 #include "core/editing/commands/DeleteSelectionCommand.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Text.h"
 #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"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLStyleElement.h"
 #include "core/html/HTMLTableRowElement.h"
 #include "core/layout/LayoutTableCell.h"
 
 namespace blink {
 
@@ skipping 10 matching lines @@
     if (!isHTMLTableRowElement(row))
         return false;
 
     for (Node* child = row->firstChild(); child; child = child->nextSibling()) {
         if (isTableCell(child) && !isTableCellEmpty(child))
             return false;
     }
     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)
     , m_mergeBlocksAfterDelete(mergeBlocksAfterDelete)
     , m_needPlaceholder(false)
     , m_expandForSpecialElements(expandForSpecialElements)
     , m_pruneStartBlockIfNecessary(false)
     , m_startsAtEmptyLine(false)
     , m_sanitizeMarkup(sanitizeMarkup)
     , m_inputType(inputType)
+    , m_referenceMovePosition(referenceMovePosition)
     , m_startBlock(nullptr)
     , m_endBlock(nullptr)
     , m_typingStyle(nullptr)
     , m_deleteIntoBlockquoteStyle(nullptr)
 {
 }
 
 DeleteSelectionCommand::DeleteSelectionCommand(const VisibleSelection& selection, bool smartDelete, bool mergeBlocksAfterDelete, bool expandForSpecialElements, bool sanitizeMarkup, InputEvent::InputType inputType)
     : CompositeEditCommand(*selection.start().document())
     , m_hasSelectionToDelete(true)
@@ skipping 714 matching lines @@
 void DeleteSelectionCommand::clearTransientState()
 {
     m_selectionToDelete = VisibleSelection();
     m_upstreamStart = Position();
     m_downstreamStart = Position();
     m_upstreamEnd = Position();
     m_downstreamEnd = Position();
     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.
 void DeleteSelectionCommand::removeRedundantBlocks(EditingState* editingState)
 {
     Node* node = m_endingPosition.computeContainerNode();
     Element* rootElement = rootEditableElement(*node);
 
     while (node != rootElement) {
         if (isRemovableBlock(node)) {
@@ skipping 13 matching lines @@
 void DeleteSelectionCommand::doApply(EditingState* editingState)
 {
     // If selection has not been set to a custom selection when the command was created,
     // use the current ending selection.
     if (!m_hasSelectionToDelete)
         m_selectionToDelete = endingSelection();
 
     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();
 
     Position downstreamEnd = mostForwardCaretPosition(m_selectionToDelete.end());
     bool rootWillStayOpenWithoutPlaceholder = downstreamEnd.computeContainerNode() == rootEditableElement(*downstreamEnd.computeContainerNode())
         || (downstreamEnd.computeContainerNode()->isTextNode() && downstreamEnd.computeContainerNode()->parentNode() == rootEditableElement(*downstreamEnd.computeContainerNode()));
     bool lineBreakAtEndOfSelectionToDelete = lineBreakExistsAtVisiblePosition(m_selectionToDelete.visibleEndDeprecated());
     m_needPlaceholder = !rootWillStayOpenWithoutPlaceholder
         && isStartOfParagraphDeprecated(m_selectionToDelete.visibleStartDeprecated(), CanCrossEditingBoundary)
         && isEndOfParagraphDeprecated(m_selectionToDelete.visibleEndDeprecated(), CanCrossEditingBoundary)
@@ skipping 70 matching lines @@
             if (editingState->isAborted())
                 return;
         }
     }
 
     rebalanceWhitespaceAt(m_endingPosition);
 
     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();
 }
 
 InputEvent::InputType DeleteSelectionCommand::inputType() const
 {
     // |DeleteSelectionCommand| could be used with Cut, Menu Bar deletion and |TypingCommand|.
     // 1. Cut and Menu Bar deletion should rely on correct |m_inputType|.
     // 2. |TypingCommand| will supply the |inputType()|, so |m_inputType| could default to |InputType::None|.
     return m_inputType;
 }
 
 // Normally deletion doesn't preserve the typing style that was present before it.  For example,
 // type a character, Bold, then delete the character and start typing.  The Bold typing style shouldn't
 // stick around.  Deletion should preserve a typing style that *it* sets, however.
 bool DeleteSelectionCommand::preservesTypingStyle() const
 {
     return m_typingStyle;
 }
 
 DEFINE_TRACE(DeleteSelectionCommand)
 {
     visitor->trace(m_selectionToDelete);
     visitor->trace(m_upstreamStart);
     visitor->trace(m_downstreamStart);
     visitor->trace(m_upstreamEnd);
     visitor->trace(m_downstreamEnd);
     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);
     visitor->trace(m_deleteIntoBlockquoteStyle);
     visitor->trace(m_startRoot);
     visitor->trace(m_endRoot);
     visitor->trace(m_startTableRow);
     visitor->trace(m_endTableRow);
     visitor->trace(m_temporaryPlaceholder);
     CompositeEditCommand::trace(visitor);
 }
 
 } // namespace blink