C++ SelectionController::isCaret方法代码示例

String DOMSelection::type() const
{
    if (!m_frame)
        return String();

    SelectionController* selection = m_frame->selection();

    // This is a WebKit DOM extension, incompatible with an IE extension
    // IE has this same attribute, but returns "none", "text" and "control"
    // http://msdn.microsoft.com/en-us/library/ms534692(VS.85).aspx
    if (selection->isNone())
        return "None";
    if (selection->isCaret())
        return "Caret";
    return "Range";
}

void TypingCommand::forwardDeleteKeyPressed(TextGranularity granularity, bool killRing)
{
#if REMOVE_MARKERS_UPON_EDITING
    document()->frame()->editor()->removeSpellAndCorrectionMarkersFromWordsToBeEdited(false);
#endif
    VisibleSelection selectionToDelete;
    VisibleSelection selectionAfterUndo;

    switch (endingSelection().selectionType()) {
    case VisibleSelection::RangeSelection:
        selectionToDelete = endingSelection();
        selectionAfterUndo = selectionToDelete;
        break;
    case VisibleSelection::CaretSelection: {
        m_smartDelete = false;

        // Handle delete at beginning-of-block case.
        // Do nothing in the case that the caret is at the start of a
        // root editable element or at the start of a document.
        SelectionController selection;
        selection.setSelection(endingSelection());
        selection.modify(SelectionController::AlterationExtend, DirectionForward, granularity);
        if (killRing && selection.isCaret() && granularity != CharacterGranularity)
            selection.modify(SelectionController::AlterationExtend, DirectionForward, CharacterGranularity);

        Position downstreamEnd = endingSelection().end().downstream();
        VisiblePosition visibleEnd = endingSelection().visibleEnd();
        if (visibleEnd == endOfParagraph(visibleEnd))
            downstreamEnd = visibleEnd.next(true).deepEquivalent().downstream();
        // When deleting tables: Select the table first, then perform the deletion
        if (downstreamEnd.node() && downstreamEnd.node()->renderer() && downstreamEnd.node()->renderer()->isTable() && !downstreamEnd.deprecatedEditingOffset()) {
            setEndingSelection(VisibleSelection(endingSelection().end(), lastDeepEditingPositionForNode(downstreamEnd.node()), DOWNSTREAM));
            typingAddedToOpenCommand(ForwardDeleteKey);
            return;
        }

        // deleting to end of paragraph when at end of paragraph needs to merge the next paragraph (if any)
        if (granularity == ParagraphBoundary && selection.selection().isCaret() && isEndOfParagraph(selection.selection().visibleEnd()))
            selection.modify(SelectionController::AlterationExtend, DirectionForward, CharacterGranularity);

        selectionToDelete = selection.selection();
        if (!startingSelection().isRange() || selectionToDelete.base() != startingSelection().start())
            selectionAfterUndo = selectionToDelete;
        else {
            // It's a little tricky to compute what the starting selection would have been in the original document.
            // We can't let the VisibleSelection class's validation kick in or it'll adjust for us based on
            // the current state of the document and we'll get the wrong result.
            Position extent = startingSelection().end();
            if (extent.node() != selectionToDelete.end().node())
                extent = selectionToDelete.extent();
            else {
                int extraCharacters;
                if (selectionToDelete.start().node() == selectionToDelete.end().node())
                    extraCharacters = selectionToDelete.end().deprecatedEditingOffset() - selectionToDelete.start().deprecatedEditingOffset();
                else
                    extraCharacters = selectionToDelete.end().deprecatedEditingOffset();
                extent = Position(extent.node(), extent.deprecatedEditingOffset() + extraCharacters, Position::PositionIsOffsetInAnchor);
            }
            selectionAfterUndo.setWithoutValidation(startingSelection().start(), extent);
        }
        break;
    }
    case VisibleSelection::NoSelection:
        ASSERT_NOT_REACHED();
        break;
    }
    
    ASSERT(!selectionToDelete.isNone());
    if (selectionToDelete.isNone())
        return;
    
    if (selectionToDelete.isCaret() || !document()->frame()->selection()->shouldDeleteSelection(selectionToDelete))
        return;
        
    if (killRing)
        document()->frame()->editor()->addToKillRing(selectionToDelete.toNormalizedRange().get(), false);
    // make undo select what was deleted
    setStartingSelection(selectionAfterUndo);
    CompositeEditCommand::deleteSelection(selectionToDelete, m_smartDelete);
    setSmartDelete(false);
    typingAddedToOpenCommand(ForwardDeleteKey);
}

void TypingCommand::deleteKeyPressed(TextGranularity granularity, bool killRing)
{
#if REMOVE_MARKERS_UPON_EDITING
    document()->frame()->editor()->removeSpellAndCorrectionMarkersFromWordsToBeEdited(false);
#endif
    VisibleSelection selectionToDelete;
    VisibleSelection selectionAfterUndo;

    switch (endingSelection().selectionType()) {
    case VisibleSelection::RangeSelection:
        selectionToDelete = endingSelection();
        selectionAfterUndo = selectionToDelete;
        break;
    case VisibleSelection::CaretSelection: {
        // After breaking out of an empty mail blockquote, we still want continue with the deletion
        // so actual content will get deleted, and not just the quote style.
        if (breakOutOfEmptyMailBlockquotedParagraph())
            typingAddedToOpenCommand(DeleteKey);

        m_smartDelete = false;

        SelectionController selection;
        selection.setSelection(endingSelection());
        selection.modify(SelectionController::AlterationExtend, DirectionBackward, granularity);
        if (killRing && selection.isCaret() && granularity != CharacterGranularity)
            selection.modify(SelectionController::AlterationExtend, DirectionBackward, CharacterGranularity);

        if (endingSelection().visibleStart().previous(true).isNull()) {
            // When the caret is at the start of the editable area in an empty list item, break out of the list item.
            if (breakOutOfEmptyListItem()) {
                typingAddedToOpenCommand(DeleteKey);
                return;
            }
            // When there are no visible positions in the editing root, delete its entire contents.
            if (endingSelection().visibleStart().next(true).isNull() && makeEditableRootEmpty()) {
                typingAddedToOpenCommand(DeleteKey);
                return;
            }
        }

        VisiblePosition visibleStart(endingSelection().visibleStart());
        // If we have a caret selection on an empty cell, we have nothing to do.
        if (isEmptyTableCell(visibleStart.deepEquivalent().node()))
            return;

        // If the caret is at the start of a paragraph after a table, move content into the last table cell.
        if (isStartOfParagraph(visibleStart) && isFirstPositionAfterTable(visibleStart.previous(true))) {
            // Unless the caret is just before a table.  We don't want to move a table into the last table cell.
            if (isLastPositionBeforeTable(visibleStart))
                return;
            // Extend the selection backward into the last cell, then deletion will handle the move.
            selection.modify(SelectionController::AlterationExtend, DirectionBackward, granularity);
        // If the caret is just after a table, select the table and don't delete anything.
        } else if (Node* table = isFirstPositionAfterTable(visibleStart)) {
            setEndingSelection(VisibleSelection(positionAfterNode(table), endingSelection().start(), DOWNSTREAM));
            typingAddedToOpenCommand(DeleteKey);
            return;
        }

        selectionToDelete = selection.selection();

        if (granularity == CharacterGranularity && selectionToDelete.end().node() == selectionToDelete.start().node() && selectionToDelete.end().deprecatedEditingOffset() - selectionToDelete.start().deprecatedEditingOffset() > 1) {
            // If there are multiple Unicode code points to be deleted, adjust the range to match platform conventions.
            selectionToDelete.setWithoutValidation(selectionToDelete.end(), selectionToDelete.end().previous(BackwardDeletion));
        }

        if (!startingSelection().isRange() || selectionToDelete.base() != startingSelection().start())
            selectionAfterUndo = selectionToDelete;
        else
            // It's a little tricky to compute what the starting selection would have been in the original document.
            // We can't let the VisibleSelection class's validation kick in or it'll adjust for us based on
            // the current state of the document and we'll get the wrong result.
            selectionAfterUndo.setWithoutValidation(startingSelection().end(), selectionToDelete.extent());
        break;
    }
    case VisibleSelection::NoSelection:
        ASSERT_NOT_REACHED();
        break;
    }
    
    ASSERT(!selectionToDelete.isNone());
    if (selectionToDelete.isNone())
        return;
    
    if (selectionToDelete.isCaret() || !document()->frame()->selection()->shouldDeleteSelection(selectionToDelete))
        return;
    
    if (killRing)
        document()->frame()->editor()->addToKillRing(selectionToDelete.toNormalizedRange().get(), false);
    // Make undo select everything that has been deleted, unless an undo will undo more than just this deletion.
    // FIXME: This behaves like TextEdit except for the case where you open with text insertion and then delete
    // more text than you insert.  In that case all of the text that was around originally should be selected.
    if (m_openedByBackwardDelete)
        setStartingSelection(selectionAfterUndo);
    CompositeEditCommand::deleteSelection(selectionToDelete, m_smartDelete);
    setSmartDelete(false);
    typingAddedToOpenCommand(DeleteKey);
}