dragcontroller.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2007, 2009 Apple 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
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"
#include "DragController.h"

#include "CSSStyleDeclaration.h"
#include "Clipboard.h"
#include "ClipboardAccessPolicy.h"
#include "DocLoader.h"
#include "Document.h"
#include "DocumentFragment.h"
#include "DragActions.h"
#include "DragClient.h"
#include "DragData.h"
#include "Editor.h"
#include "EditorClient.h"
#include "Element.h"
#include "EventHandler.h"
#include "FloatRect.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameView.h"
#include "HTMLAnchorElement.h"
#include "HTMLInputElement.h"
#include "HTMLNames.h"
#include "HitTestResult.h"
#include "Image.h"
#include "MoveSelectionCommand.h"
#include "Node.h"
#include "Page.h"
#include "RenderFileUploadControl.h"
#include "RenderImage.h"
#include "ReplaceSelectionCommand.h"
#include "ResourceRequest.h"
#include "SelectionController.h"
#include "Settings.h"
#include "Text.h"
#include "htmlediting.h"
#include "markup.h"
#include <wtf/CurrentTime.h>
#include <wtf/RefPtr.h>

namespace WebCore {

static PlatformMouseEvent createMouseEvent(DragData* dragData)
{
    // FIXME: We should fake modifier keys here.
    return PlatformMouseEvent(dragData->clientPosition(), dragData->globalPosition(),
                              LeftButton, MouseEventMoved, 0, false, false, false, false, currentTime());

}
    
DragController::DragController(Page* page, DragClient* client)
    : m_page(page)
    , m_client(client)
    , m_document(0)
    , m_dragInitiator(0)
    , m_dragDestinationAction(DragDestinationActionNone)
    , m_dragSourceAction(DragSourceActionNone)
    , m_didInitiateDrag(false)
    , m_isHandlingDrag(false)
    , m_dragOperation(DragOperationNone)
{
}
    
DragController::~DragController()
{   
    m_client->dragControllerDestroyed();
}
    
static PassRefPtr<DocumentFragment> documentFragmentFromDragData(DragData* dragData, RefPtr<Range> context,
                                          bool allowPlainText, bool& chosePlainText)
{
    ASSERT(dragData);
    chosePlainText = false;

    Document* document = context->ownerDocument();
    ASSERT(document);
    if (document && dragData->containsCompatibleContent()) {
        if (PassRefPtr<DocumentFragment> fragment = dragData->asFragment(document))
            return fragment;

        if (dragData->containsURL()) {
            String title;
            String url = dragData->asURL(&title);
            if (!url.isEmpty()) {
                RefPtr<HTMLAnchorElement> anchor = new HTMLAnchorElement(document);
                anchor->setHref(url);
                ExceptionCode ec;
                RefPtr<Node> anchorText = document->createTextNode(title);
                anchor->appendChild(anchorText, ec);
                RefPtr<DocumentFragment> fragment = document->createDocumentFragment();
                fragment->appendChild(anchor, ec);
                return fragment.get();
            }
        }
    }
    if (allowPlainText && dragData->containsPlainText()) {
        chosePlainText = true;
        return createFragmentFromText(context.get(), dragData->asPlainText()).get();
    }
    
    return 0;
}

bool DragController::dragIsMove(SelectionController* selection)
{
    return m_document == m_dragInitiator && selection->isContentEditable() && !isCopyKeyDown();
}

void DragController::cancelDrag()
{
    m_page->dragCaretController()->clear();
}

void DragController::dragEnded()
{
    m_dragInitiator = 0;
    m_didInitiateDrag = false; 
    m_page->dragCaretController()->clear(); 
}    

DragOperation DragController::dragEntered(DragData* dragData) 
{
    return dragEnteredOrUpdated(dragData);
}
    
void DragController::dragExited(DragData* dragData) 
{   
    ASSERT(dragData);
    Frame* mainFrame = m_page->mainFrame();
    
    if (RefPtr<FrameView> v = mainFrame->view()) {
        ClipboardAccessPolicy policy = mainFrame->loader()->baseURL().isLocalFile() ? ClipboardReadable : ClipboardTypesReadable;
        RefPtr<Clipboard> clipboard = dragData->createClipboard(policy);
        clipboard->setSourceOperation(dragData->draggingSourceOperationMask());
        mainFrame->eventHandler()->cancelDragAndDrop(createMouseEvent(dragData), clipboard.get());
        clipboard->setAccessPolicy(ClipboardNumb);    // invalidate clipboard here for security
    }

    cancelDrag();
    m_document = 0;
}
    
DragOperation DragController::dragUpdated(DragData* dragData) 
{
    return dragEnteredOrUpdated(dragData);
}
    
bool DragController::performDrag(DragData* dragData)
{   
    ASSERT(dragData);
    m_document = m_page->mainFrame()->documentAtPoint(dragData->clientPosition());
    if (m_isHandlingDrag) {
        ASSERT(m_dragDestinationAction & DragDestinationActionDHTML);
        m_client->willPerformDragDestinationAction(DragDestinationActionDHTML, dragData);
        RefPtr<Frame> mainFrame = m_page->mainFrame();
        if (mainFrame->view()) {
            // Sending an event can result in the destruction of the view and part.
            RefPtr<Clipboard> clipboard = dragData->createClipboard(ClipboardReadable);
            clipboard->setSourceOperation(dragData->draggingSourceOperationMask());
            mainFrame->eventHandler()->performDragAndDrop(createMouseEvent(dragData), clipboard.get());
            clipboard->setAccessPolicy(ClipboardNumb);    // invalidate clipboard here for security
        }
        m_document = 0;
        return true;
    } 
    
    if ((m_dragDestinationAction & DragDestinationActionEdit) && concludeEditDrag(dragData)) {
        m_document = 0;
        return true;
    }
    
    m_document = 0;

    if (operationForLoad(dragData) == DragOperationNone)
        return false;

    m_client->willPerformDragDestinationAction(DragDestinationActionLoad, dragData);
    m_page->mainFrame()->loader()->load(ResourceRequest(dragData->asURL()), false);
    return true;
}
    
DragOperation DragController::dragEnteredOrUpdated(DragData* dragData)
{
    ASSERT(dragData);
    IntPoint windowPoint = dragData->clientPosition();
    
    Document* newDraggingDoc = 0;
    if (Frame* frame = m_page->mainFrame())
        newDraggingDoc = frame->documentAtPoint(windowPoint);
    if (m_document != newDraggingDoc) {
        if (m_document)
            cancelDrag();
        m_document = newDraggingDoc;
    }
    
    m_dragDestinationAction = m_client->actionMaskForDrag(dragData);
    
    DragOperation operation = DragOperationNone;
    
    if (m_dragDestinationAction == DragDestinationActionNone)
        cancelDrag();
    else {
        operation = tryDocumentDrag(dragData, m_dragDestinationAction);
        if (operation == DragOperationNone && (m_dragDestinationAction & DragDestinationActionLoad))
            return operationForLoad(dragData);
    }
    
    return operation;
}

static HTMLInputElement* asFileInput(Node* node)
{
    ASSERT(node);
    
    // The button for a FILE input is a sub element with no set input type
    // In order to get around this problem we assume any non-FILE input element
    // is this internal button, and try querying the shadow parent node.
    if (node->hasTagName(HTMLNames::inputTag) && node->isShadowNode() && static_cast<HTMLInputElement*>(node)->inputType() != HTMLInputElement::FILE)
      node = node->shadowParentNode();
    
    if (!node || !node->hasTagName(HTMLNames::inputTag))
        return 0;
    
    HTMLInputElement* inputElem = static_cast<HTMLInputElement*>(node);
    if (inputElem->inputType() == HTMLInputElement::FILE)
        return inputElem;
    
    return 0;
}
    
DragOperation DragController::tryDocumentDrag(DragData* dragData, DragDestinationAction actionMask)
{
    ASSERT(dragData);
    
    if (!m_document)
        return DragOperationNone;
    
    DragOperation operation = DragOperationNone;
    if (actionMask & DragDestinationActionDHTML)
        operation = tryDHTMLDrag(dragData);
    m_isHandlingDrag = operation != DragOperationNone; 

    RefPtr<FrameView> frameView = m_document->view();
    if (!frameView)
        return operation;
    
    if ((actionMask & DragDestinationActionEdit) && !m_isHandlingDrag && canProcessDrag(dragData)) {
        if (dragData->containsColor()) 
            return DragOperationGeneric;
        
        IntPoint dragPos = dragData->clientPosition();
        IntPoint point = frameView->windowToContents(dragPos);
        Element* element = m_document->elementFromPoint(point.x(), point.y());
        ASSERT(element);
        Frame* innerFrame = element->document()->frame();
        ASSERT(innerFrame);
        if (!asFileInput(element)) {
            VisibleSelection dragCaret;
            if (Frame* frame = m_document->frame())
                dragCaret = frame->visiblePositionForPoint(point);
            m_page->dragCaretController()->setSelection(dragCaret);
        }
        
        return dragIsMove(innerFrame->selection()) ? DragOperationMove : DragOperationCopy;
    } 
    
    m_page->dragCaretController()->clear();
    return operation;
}

DragSourceAction DragController::delegateDragSourceAction(const IntPoint& windowPoint)
{  
    m_dragSourceAction = m_client->dragSourceActionMaskForPoint(windowPoint);
    return m_dragSourceAction;
}
    
DragOperation DragController::operationForLoad(DragData* dragData)
{
    ASSERT(dragData);
    Document* doc = 0;
    doc = m_page->mainFrame()->documentAtPoint(dragData->clientPosition());
    if (doc && (m_didInitiateDrag || doc->isPluginDocument() || (doc->frame() && doc->frame()->editor()->clientIsEditable())))
        return DragOperationNone;
    return dragOperation(dragData);
}

static bool setSelectionToDragCaret(Frame* frame, VisibleSelection& dragCaret, RefPtr<Range>& range, const IntPoint& point)
{
    frame->selection()->setSelection(dragCaret);
    if (frame->selection()->isNone()) {
        dragCaret = frame->visiblePositionForPoint(point);
        frame->selection()->setSelection(dragCaret);
        range = dragCaret.toNormalizedRange();
    }
    return !frame->selection()->isNone() && frame->selection()->isContentEditable();
}

bool DragController::concludeEditDrag(DragData* dragData)
{
    ASSERT(dragData);
    ASSERT(!m_isHandlingDrag);
    
    if (!m_document)
        return false;
    
    IntPoint point = m_document->view()->windowToContents(dragData->clientPosition());
    Element* element =  m_document->elementFromPoint(point.x(), point.y());
    ASSERT(element);
    Frame* innerFrame = element->ownerDocument()->frame();
    ASSERT(innerFrame);    

    if (dragData->containsColor()) {
        Color color = dragData->asColor();
        if (!color.isValid())
            return false;
        if (!innerFrame)
            return false;
        RefPtr<Range> innerRange = innerFrame->selection()->toNormalizedRange();
        RefPtr<CSSStyleDeclaration> style = m_document->createCSSStyleDeclaration();
        ExceptionCode ec;
        style->setProperty("color", color.name(), ec);
        if (!innerFrame->editor()->shouldApplyStyle(style.get(), innerRange.get()))
            return false;
        m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
        innerFrame->editor()->applyStyle(style.get(), EditActionSetColor);
        return true;
    }
    
    if (!m_page->dragController()->canProcessDrag(dragData)) {
        m_page->dragCaretController()->clear();
        return false;
    }
    
    if (HTMLInputElement* fileInput = asFileInput(element)) {
        
        if (!fileInput->isEnabled())
            return false;
        
        if (!dragData->containsFiles())
            return false;
        
        Vector<String> filenames;
        dragData->asFilenames(filenames);
        if (filenames.isEmpty())
            return false;
        
        // Ugly.  For security none of the API's available to us to set the input value 
        // on file inputs.  Even forcing a change in HTMLInputElement doesn't work as
        // RenderFileUploadControl clears the file when doing updateFromElement()
        RenderFileUploadControl* renderer = static_cast<RenderFileUploadControl*>(fileInput->renderer());
        
        if (!renderer)
            return false;
        
        renderer->receiveDroppedFiles(filenames);
        return true;
    }

    VisibleSelection dragCaret(m_page->dragCaretController()->selection());
    m_page->dragCaretController()->clear();
    RefPtr<Range> range = dragCaret.toNormalizedRange();
    
    // For range to be null a WebKit client must have done something bad while
    // manually controlling drag behaviour
    if (!range)