bool EditorClient::executePendingEditorCommands(Frame* frame, bool allowTextInsertion)
{
    Vector<Editor::Command> commands;
    for (size_t i = 0; i < m_pendingEditorCommands.size(); i++) {
        Editor::Command command = frame->editor()->command(m_pendingEditorCommands.at(i).utf8().data());
        if (command.isTextInsertion() && !allowTextInsertion)
            return false;

        commands.append(command);
    }

    bool success = true;
    for (size_t i = 0; i < commands.size(); i++) {
        if (!commands.at(i).execute()) {
            success = false;
            break;
        }
    }

    m_pendingEditorCommands.clear();

    // If we successfully completed all editor commands, then
    // this signals a canceling of the composition.
    if (success)
        clearPendingComposition();

    return success;
}

static void handleKeyDown(Frame& frame, KeyboardEvent& event, const PlatformKeyboardEvent&)
{
    String commandName = interpretKeyEvent(event);
    if (commandName.isEmpty())
        return;

    // We shouldn't insert text through the editor. Let WebCore decide
    // how to handle that (say, Tab, which could also be used to
    // change focus).
    Editor::Command command = frame.editor().command(commandName);
    if (command.isTextInsertion())
        return;

    command.execute();
    event.setDefaultHandled();
}

bool WebEditorClient::executePendingEditorCommands(Frame* frame, const Vector<WTF::String>& pendingEditorCommands, bool allowTextInsertion)
{
    Vector<Editor::Command> commands;
    for (auto& commandString : pendingEditorCommands) {
        Editor::Command command = frame->editor().command(commandString.utf8().data());
        if (command.isTextInsertion() && !allowTextInsertion)
            return false;

        commands.append(WTF::move(command));
    }

    for (auto& command : commands) {
        if (!command.execute())
            return false;
    }

    return true;
}

void EditorClientAndroid::handleKeyboardEvent(KeyboardEvent* event) {
    ASSERT(m_page);
    Frame* frame = m_page->focusController()->focusedOrMainFrame();
    if (!frame)
        return;

    const PlatformKeyboardEvent* keyEvent = event->keyEvent();
    // TODO: If the event is not coming from Android Java, e.g. from JavaScript,
    // PlatformKeyboardEvent is null. We should support this later.
    if (!keyEvent)
        return;

    Editor::Command command = frame->editor()->command(interpretKeyEvent(event));
    if (keyEvent->type() == PlatformKeyboardEvent::RawKeyDown) {
        if (!command.isTextInsertion() && command.execute(event)) {
            // This function mimics the Windows version.  However, calling event->setDefaultHandled()
            // prevents the javascript key events for the delete key from happening.
            // Update: Safari doesn't send delete key events to javascript so
            // we will mimic that behavior.
            event->setDefaultHandled();
        }
        return;
    }
    
    if (command.execute(event)) {
        event->setDefaultHandled();
        return;
    }
    
    // Don't insert null or control characters as they can result in unexpected behaviour
    if (event->charCode() < ' ')
        return;
    
    if (frame->editor()->insertText(keyEvent->text(), event))
        event->setDefaultHandled();
}

void ContextMenu::checkOrEnableIfNeeded(ContextMenuItem& item) const
{
    if (item.type() == SeparatorType)
        return;
    
    Frame* frame = m_hitTestResult.innerNonSharedNode()->document()->frame();
    if (!frame)
        return;

    bool shouldEnable = true;
    bool shouldCheck = false; 

    switch (item.action()) {
        case ContextMenuItemTagCheckSpelling:
            shouldEnable = frame->editor()->canEdit();
            break;
        case ContextMenuItemTagDefaultDirection:
            shouldCheck = false;
            shouldEnable = false;
            break;
        case ContextMenuItemTagLeftToRight:
        case ContextMenuItemTagRightToLeft: {
            ExceptionCode ec = 0;
            RefPtr<CSSStyleDeclaration> style = frame->document()->createCSSStyleDeclaration();
            String direction = item.action() == ContextMenuItemTagLeftToRight ? "ltr" : "rtl";
            style->setProperty(CSSPropertyDirection, direction, false, ec);
            shouldCheck = frame->editor()->selectionHasStyle(style.get()) != FalseTriState;
            shouldEnable = true;
            break;
        }
        case ContextMenuItemTagTextDirectionDefault: {
            Editor::Command command = frame->editor()->command("MakeTextWritingDirectionNatural");
            shouldCheck = command.state() == TrueTriState;
            shouldEnable = command.isEnabled();
            break;
        }
        case ContextMenuItemTagTextDirectionLeftToRight: {
            Editor::Command command = frame->editor()->command("MakeTextWritingDirectionLeftToRight");
            shouldCheck = command.state() == TrueTriState;
            shouldEnable = command.isEnabled();
            break;
        }
        case ContextMenuItemTagTextDirectionRightToLeft: {
            Editor::Command command = frame->editor()->command("MakeTextWritingDirectionRightToLeft");
            shouldCheck = command.state() == TrueTriState;
            shouldEnable = command.isEnabled();
            break;
        }
        case ContextMenuItemTagCopy:
            shouldEnable = frame->editor()->canDHTMLCopy() || frame->editor()->canCopy();
            break;
        case ContextMenuItemTagCut:
            shouldEnable = frame->editor()->canDHTMLCut() || frame->editor()->canCut();
            break;
        case ContextMenuItemTagIgnoreSpelling:
        case ContextMenuItemTagLearnSpelling:
            shouldEnable = frame->selection()->isRange();
            break;
        case ContextMenuItemTagPaste:
            shouldEnable = frame->editor()->canDHTMLPaste() || frame->editor()->canPaste();
            break;
#if PLATFORM(GTK)
        case ContextMenuItemTagDelete:
            shouldEnable = frame->editor()->canDelete();
            break;
        case ContextMenuItemTagSelectAll:
        case ContextMenuItemTagInputMethods:
        case ContextMenuItemTagUnicode:
            shouldEnable = true;
            break;
#endif
        case ContextMenuItemTagUnderline: {
            ExceptionCode ec = 0;
            RefPtr<CSSStyleDeclaration> style = frame->document()->createCSSStyleDeclaration();
            style->setProperty(CSSPropertyWebkitTextDecorationsInEffect, "underline", false, ec);
            shouldCheck = frame->editor()->selectionHasStyle(style.get()) != FalseTriState;
            shouldEnable = frame->editor()->canEditRichly();
            break;
        }
        case ContextMenuItemTagLookUpInDictionary:
            shouldEnable = frame->selection()->isRange();
            break;
        case ContextMenuItemTagCheckGrammarWithSpelling:
#ifndef BUILDING_ON_TIGER
            if (frame->editor()->isGrammarCheckingEnabled())
                shouldCheck = true;
            shouldEnable = true;
#endif
            break;
        case ContextMenuItemTagItalic: {
            ExceptionCode ec = 0;
            RefPtr<CSSStyleDeclaration> style = frame->document()->createCSSStyleDeclaration();
            style->setProperty(CSSPropertyFontStyle, "italic", false, ec);
            shouldCheck = frame->editor()->selectionHasStyle(style.get()) != FalseTriState;
            shouldEnable = frame->editor()->canEditRichly();
            break;
        }
        case ContextMenuItemTagBold: {
            ExceptionCode ec = 0;
            RefPtr<CSSStyleDeclaration> style = frame->document()->createCSSStyleDeclaration();
//.........这里部分代码省略.........