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1 /*
2  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "config.h"
27 #include "DragController.h"
28 
29 #if ENABLE(DRAG_SUPPORT)
30 #include "CSSStyleDeclaration.h"
31 #include "Clipboard.h"
32 #include "ClipboardAccessPolicy.h"
33 #include "CachedResourceLoader.h"
34 #include "Document.h"
35 #include "DocumentFragment.h"
36 #include "DragActions.h"
37 #include "DragClient.h"
38 #include "DragData.h"
39 #include "Editor.h"
40 #include "EditorClient.h"
41 #include "Element.h"
42 #include "EventHandler.h"
43 #include "FloatRect.h"
44 #include "Frame.h"
45 #include "FrameLoader.h"
46 #include "FrameView.h"
47 #include "HTMLAnchorElement.h"
48 #include "HTMLInputElement.h"
49 #include "HTMLNames.h"
50 #include "HitTestRequest.h"
51 #include "HitTestResult.h"
52 #include "Image.h"
53 #include "MoveSelectionCommand.h"
54 #include "Node.h"
55 #include "Page.h"
56 #include "PlatformKeyboardEvent.h"
57 #include "RenderFileUploadControl.h"
58 #include "RenderImage.h"
59 #include "RenderLayer.h"
60 #include "RenderView.h"
61 #include "ReplaceSelectionCommand.h"
62 #include "ResourceRequest.h"
63 #include "SelectionController.h"
64 #include "Settings.h"
65 #include "Text.h"
66 #include "TextEvent.h"
67 #include "htmlediting.h"
68 #include "markup.h"
69 #include <wtf/CurrentTime.h>
70 #include <wtf/RefPtr.h>
71 
72 namespace WebCore {
73 
createMouseEvent(DragData * dragData)74 static PlatformMouseEvent createMouseEvent(DragData* dragData)
75 {
76     bool shiftKey, ctrlKey, altKey, metaKey;
77     shiftKey = ctrlKey = altKey = metaKey = false;
78     PlatformKeyboardEvent::getCurrentModifierState(shiftKey, ctrlKey, altKey, metaKey);
79     return PlatformMouseEvent(dragData->clientPosition(), dragData->globalPosition(),
80                               LeftButton, MouseEventMoved, 0, shiftKey, ctrlKey, altKey,
81                               metaKey, currentTime());
82 }
83 
DragController(Page * page,DragClient * client)84 DragController::DragController(Page* page, DragClient* client)
85     : m_page(page)
86     , m_client(client)
87     , m_documentUnderMouse(0)
88     , m_dragInitiator(0)
89     , m_dragDestinationAction(DragDestinationActionNone)
90     , m_dragSourceAction(DragSourceActionNone)
91     , m_didInitiateDrag(false)
92     , m_isHandlingDrag(false)
93     , m_sourceDragOperation(DragOperationNone)
94 {
95 }
96 
~DragController()97 DragController::~DragController()
98 {
99     m_client->dragControllerDestroyed();
100 }
101 
documentFragmentFromDragData(DragData * dragData,Frame * frame,RefPtr<Range> context,bool allowPlainText,bool & chosePlainText)102 static PassRefPtr<DocumentFragment> documentFragmentFromDragData(DragData* dragData, Frame* frame, RefPtr<Range> context,
103                                           bool allowPlainText, bool& chosePlainText)
104 {
105     ASSERT(dragData);
106     chosePlainText = false;
107 
108     Document* document = context->ownerDocument();
109     ASSERT(document);
110     if (document && dragData->containsCompatibleContent()) {
111         if (PassRefPtr<DocumentFragment> fragment = dragData->asFragment(frame, context, allowPlainText, chosePlainText))
112             return fragment;
113 
114         if (dragData->containsURL(frame, DragData::DoNotConvertFilenames)) {
115             String title;
116             String url = dragData->asURL(frame, DragData::DoNotConvertFilenames, &title);
117             if (!url.isEmpty()) {
118                 RefPtr<HTMLAnchorElement> anchor = HTMLAnchorElement::create(document);
119                 anchor->setHref(url);
120                 if (title.isEmpty()) {
121                     // Try the plain text first because the url might be normalized or escaped.
122                     if (dragData->containsPlainText())
123                         title = dragData->asPlainText(frame);
124                     if (title.isEmpty())
125                         title = url;
126                 }
127                 RefPtr<Node> anchorText = document->createTextNode(title);
128                 ExceptionCode ec;
129                 anchor->appendChild(anchorText, ec);
130                 RefPtr<DocumentFragment> fragment = document->createDocumentFragment();
131                 fragment->appendChild(anchor, ec);
132                 return fragment.get();
133             }
134         }
135     }
136     if (allowPlainText && dragData->containsPlainText()) {
137         chosePlainText = true;
138         return createFragmentFromText(context.get(), dragData->asPlainText(frame)).get();
139     }
140 
141     return 0;
142 }
143 
dragIsMove(SelectionController * selection,DragData * dragData)144 bool DragController::dragIsMove(SelectionController* selection, DragData* dragData)
145 {
146     return m_documentUnderMouse == m_dragInitiator && selection->isContentEditable() && !isCopyKeyDown(dragData);
147 }
148 
149 // FIXME: This method is poorly named.  We're just clearing the selection from the document this drag is exiting.
cancelDrag()150 void DragController::cancelDrag()
151 {
152     m_page->dragCaretController()->clear();
153 }
154 
dragEnded()155 void DragController::dragEnded()
156 {
157     m_dragInitiator = 0;
158     m_didInitiateDrag = false;
159     m_page->dragCaretController()->clear();
160 }
161 
dragEntered(DragData * dragData)162 DragOperation DragController::dragEntered(DragData* dragData)
163 {
164     return dragEnteredOrUpdated(dragData);
165 }
166 
dragExited(DragData * dragData)167 void DragController::dragExited(DragData* dragData)
168 {
169     ASSERT(dragData);
170     Frame* mainFrame = m_page->mainFrame();
171 
172     if (RefPtr<FrameView> v = mainFrame->view()) {
173         ClipboardAccessPolicy policy = (!m_documentUnderMouse || m_documentUnderMouse->securityOrigin()->isLocal()) ? ClipboardReadable : ClipboardTypesReadable;
174         RefPtr<Clipboard> clipboard = Clipboard::create(policy, dragData, mainFrame);
175         clipboard->setSourceOperation(dragData->draggingSourceOperationMask());
176         mainFrame->eventHandler()->cancelDragAndDrop(createMouseEvent(dragData), clipboard.get());
177         clipboard->setAccessPolicy(ClipboardNumb);    // invalidate clipboard here for security
178     }
179     mouseMovedIntoDocument(0);
180 }
181 
dragUpdated(DragData * dragData)182 DragOperation DragController::dragUpdated(DragData* dragData)
183 {
184     return dragEnteredOrUpdated(dragData);
185 }
186 
performDrag(DragData * dragData)187 bool DragController::performDrag(DragData* dragData)
188 {
189     ASSERT(dragData);
190     m_documentUnderMouse = m_page->mainFrame()->documentAtPoint(dragData->clientPosition());
191     if (m_isHandlingDrag) {
192         ASSERT(m_dragDestinationAction & DragDestinationActionDHTML);
193         m_client->willPerformDragDestinationAction(DragDestinationActionDHTML, dragData);
194         RefPtr<Frame> mainFrame = m_page->mainFrame();
195         if (mainFrame->view()) {
196             // Sending an event can result in the destruction of the view and part.
197             RefPtr<Clipboard> clipboard = Clipboard::create(ClipboardReadable, dragData, mainFrame.get());
198             clipboard->setSourceOperation(dragData->draggingSourceOperationMask());
199             mainFrame->eventHandler()->performDragAndDrop(createMouseEvent(dragData), clipboard.get());
200             clipboard->setAccessPolicy(ClipboardNumb);    // invalidate clipboard here for security
201         }
202         m_documentUnderMouse = 0;
203         return true;
204     }
205 
206     if ((m_dragDestinationAction & DragDestinationActionEdit) && concludeEditDrag(dragData)) {
207         m_documentUnderMouse = 0;
208         return true;
209     }
210 
211     m_documentUnderMouse = 0;
212 
213     if (operationForLoad(dragData) == DragOperationNone)
214         return false;
215 
216     m_client->willPerformDragDestinationAction(DragDestinationActionLoad, dragData);
217     m_page->mainFrame()->loader()->load(ResourceRequest(dragData->asURL(m_page->mainFrame())), false);
218     return true;
219 }
220 
mouseMovedIntoDocument(Document * newDocument)221 void DragController::mouseMovedIntoDocument(Document* newDocument)
222 {
223     if (m_documentUnderMouse == newDocument)
224         return;
225 
226     // If we were over another document clear the selection
227     if (m_documentUnderMouse)
228         cancelDrag();
229     m_documentUnderMouse = newDocument;
230 }
231 
dragEnteredOrUpdated(DragData * dragData)232 DragOperation DragController::dragEnteredOrUpdated(DragData* dragData)
233 {
234     ASSERT(dragData);
235     ASSERT(m_page->mainFrame()); // It is not possible in Mac WebKit to have a Page without a mainFrame()
236     mouseMovedIntoDocument(m_page->mainFrame()->documentAtPoint(dragData->clientPosition()));
237 
238     m_dragDestinationAction = m_client->actionMaskForDrag(dragData);
239     if (m_dragDestinationAction == DragDestinationActionNone) {
240         cancelDrag(); // FIXME: Why not call mouseMovedIntoDocument(0)?
241         return DragOperationNone;
242     }
243 
244     DragOperation operation = DragOperationNone;
245     bool handledByDocument = tryDocumentDrag(dragData, m_dragDestinationAction, operation);
246     if (!handledByDocument && (m_dragDestinationAction & DragDestinationActionLoad))
247         return operationForLoad(dragData);
248     return operation;
249 }
250 
asFileInput(Node * node)251 static HTMLInputElement* asFileInput(Node* node)
252 {
253     ASSERT(node);
254 
255     // The button for a FILE input is a sub element with no set input type
256     // In order to get around this problem we assume any non-FILE input element
257     // is this internal button, and try querying the shadow parent node.
258     if (node->hasTagName(HTMLNames::inputTag) && node->isShadowRoot() && !static_cast<HTMLInputElement*>(node)->isFileUpload())
259         node = node->shadowHost();
260 
261     if (!node || !node->hasTagName(HTMLNames::inputTag))
262         return 0;
263 
264     HTMLInputElement* inputElement = static_cast<HTMLInputElement*>(node);
265     if (!inputElement->isFileUpload())
266         return 0;
267 
268     return inputElement;
269 }
270 
271 // This can return null if an empty document is loaded.
elementUnderMouse(Document * documentUnderMouse,const IntPoint & p)272 static Element* elementUnderMouse(Document* documentUnderMouse, const IntPoint& p)
273 {
274     Frame* frame = documentUnderMouse->frame();
275     float zoomFactor = frame ? frame->pageZoomFactor() : 1;
276     IntPoint point = roundedIntPoint(FloatPoint(p.x() * zoomFactor, p.y() * zoomFactor));
277 
278     HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active);
279     HitTestResult result(point);
280     documentUnderMouse->renderView()->layer()->hitTest(request, result);
281 
282     Node* n = result.innerNode();
283     while (n && !n->isElementNode())
284         n = n->parentNode();
285     if (n)
286         n = n->shadowAncestorNode();
287 
288     return static_cast<Element*>(n);
289 }
290 
tryDocumentDrag(DragData * dragData,DragDestinationAction actionMask,DragOperation & operation)291 bool DragController::tryDocumentDrag(DragData* dragData, DragDestinationAction actionMask, DragOperation& operation)
292 {
293     ASSERT(dragData);
294 
295     if (!m_documentUnderMouse)
296         return false;
297 
298     if (m_dragInitiator && !m_documentUnderMouse->securityOrigin()->canReceiveDragData(m_dragInitiator->securityOrigin()))
299         return false;
300 
301     m_isHandlingDrag = false;
302     if (actionMask & DragDestinationActionDHTML) {
303         m_isHandlingDrag = tryDHTMLDrag(dragData, operation);
304         // Do not continue if m_documentUnderMouse has been reset by tryDHTMLDrag.
305         // tryDHTMLDrag fires dragenter event. The event listener that listens
306         // to this event may create a nested message loop (open a modal dialog),
307         // which could process dragleave event and reset m_documentUnderMouse in
308         // dragExited.
309         if (!m_documentUnderMouse)
310             return false;
311     }
312 
313     // It's unclear why this check is after tryDHTMLDrag.
314     // We send drag events in tryDHTMLDrag and that may be the reason.
315     RefPtr<FrameView> frameView = m_documentUnderMouse->view();
316     if (!frameView)
317         return false;
318 
319     if (m_isHandlingDrag) {
320         m_page->dragCaretController()->clear();
321         return true;
322     } else if ((actionMask & DragDestinationActionEdit) && canProcessDrag(dragData)) {
323         if (dragData->containsColor()) {
324             operation = DragOperationGeneric;
325             return true;
326         }
327 
328         IntPoint point = frameView->windowToContents(dragData->clientPosition());
329         Element* element = elementUnderMouse(m_documentUnderMouse.get(), point);
330         if (!element)
331             return false;
332         if (!asFileInput(element)) {
333             VisibleSelection dragCaret = m_documentUnderMouse->frame()->visiblePositionForPoint(point);
334             m_page->dragCaretController()->setSelection(dragCaret);
335         }
336 
337         Frame* innerFrame = element->document()->frame();
338         operation = dragIsMove(innerFrame->selection(), dragData) ? DragOperationMove : DragOperationCopy;
339         return true;
340     }
341     // If we're not over an editable region, make sure we're clearing any prior drag cursor.
342     m_page->dragCaretController()->clear();
343     return false;
344 }
345 
delegateDragSourceAction(const IntPoint & windowPoint)346 DragSourceAction DragController::delegateDragSourceAction(const IntPoint& windowPoint)
347 {
348     m_dragSourceAction = m_client->dragSourceActionMaskForPoint(windowPoint);
349     return m_dragSourceAction;
350 }
351 
operationForLoad(DragData * dragData)352 DragOperation DragController::operationForLoad(DragData* dragData)
353 {
354     ASSERT(dragData);
355     Document* doc = m_page->mainFrame()->documentAtPoint(dragData->clientPosition());
356     if (doc && (m_didInitiateDrag || doc->isPluginDocument() || doc->rendererIsEditable()))
357         return DragOperationNone;
358     return dragOperation(dragData);
359 }
360 
setSelectionToDragCaret(Frame * frame,VisibleSelection & dragCaret,RefPtr<Range> & range,const IntPoint & point)361 static bool setSelectionToDragCaret(Frame* frame, VisibleSelection& dragCaret, RefPtr<Range>& range, const IntPoint& point)
362 {
363     frame->selection()->setSelection(dragCaret);
364     if (frame->selection()->isNone()) {
365         dragCaret = frame->visiblePositionForPoint(point);
366         frame->selection()->setSelection(dragCaret);
367         range = dragCaret.toNormalizedRange();
368     }
369     return !frame->selection()->isNone() && frame->selection()->isContentEditable();
370 }
371 
dispatchTextInputEventFor(Frame * innerFrame,DragData * dragData)372 bool DragController::dispatchTextInputEventFor(Frame* innerFrame, DragData* dragData)
373 {
374     ASSERT(!m_page->dragCaretController()->isNone());
375     VisibleSelection dragCaret(m_page->dragCaretController()->selection());
376     String text = dragCaret.isContentRichlyEditable() ? "" : dragData->asPlainText(innerFrame);
377     Node* target = innerFrame->editor()->findEventTargetFrom(dragCaret);
378     ExceptionCode ec = 0;
379     return target->dispatchEvent(TextEvent::createForDrop(innerFrame->domWindow(), text), ec);
380 }
381 
concludeEditDrag(DragData * dragData)382 bool DragController::concludeEditDrag(DragData* dragData)
383 {
384     ASSERT(dragData);
385     ASSERT(!m_isHandlingDrag);
386 
387     if (!m_documentUnderMouse)
388         return false;
389 
390     IntPoint point = m_documentUnderMouse->view()->windowToContents(dragData->clientPosition());
391     Element* element = elementUnderMouse(m_documentUnderMouse.get(), point);
392     if (!element)
393         return false;
394     Frame* innerFrame = element->ownerDocument()->frame();
395     ASSERT(innerFrame);
396 
397     if (!m_page->dragCaretController()->isNone() && !dispatchTextInputEventFor(innerFrame, dragData))
398         return true;
399 
400     if (dragData->containsColor()) {
401         Color color = dragData->asColor();
402         if (!color.isValid())
403             return false;
404         RefPtr<Range> innerRange = innerFrame->selection()->toNormalizedRange();
405         RefPtr<CSSStyleDeclaration> style = m_documentUnderMouse->createCSSStyleDeclaration();
406         ExceptionCode ec;
407         style->setProperty("color", color.serialized(), ec);
408         if (!innerFrame->editor()->shouldApplyStyle(style.get(), innerRange.get()))
409             return false;
410         m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
411         innerFrame->editor()->applyStyle(style.get(), EditActionSetColor);
412         return true;
413     }
414 
415     if (!m_page->dragController()->canProcessDrag(dragData)) {
416         m_page->dragCaretController()->clear();
417         return false;
418     }
419 
420     if (HTMLInputElement* fileInput = asFileInput(element)) {
421         if (fileInput->disabled())
422             return false;
423 
424         if (!dragData->containsFiles())
425             return false;
426 
427         Vector<String> filenames;
428         dragData->asFilenames(filenames);
429         if (filenames.isEmpty())
430             return false;
431 
432         // Ugly. For security none of the APIs available to us can set the input value
433         // on file inputs. Even forcing a change in HTMLInputElement doesn't work as
434         // RenderFileUploadControl clears the file when doing updateFromElement().
435         RenderFileUploadControl* renderer = toRenderFileUploadControl(fileInput->renderer());
436         if (!renderer)
437             return false;
438 
439         renderer->receiveDroppedFiles(filenames);
440         return true;
441     }
442 
443     VisibleSelection dragCaret(m_page->dragCaretController()->selection());
444     m_page->dragCaretController()->clear();
445     RefPtr<Range> range = dragCaret.toNormalizedRange();
446 
447     // For range to be null a WebKit client must have done something bad while
448     // manually controlling drag behaviour
449     if (!range)
450         return false;
451     CachedResourceLoader* cachedResourceLoader = range->ownerDocument()->cachedResourceLoader();
452     cachedResourceLoader->setAllowStaleResources(true);
453     if (dragIsMove(innerFrame->selection(), dragData) || dragCaret.isContentRichlyEditable()) {
454         bool chosePlainText = false;
455         RefPtr<DocumentFragment> fragment = documentFragmentFromDragData(dragData, innerFrame, range, true, chosePlainText);
456         if (!fragment || !innerFrame->editor()->shouldInsertFragment(fragment, range, EditorInsertActionDropped)) {
457             cachedResourceLoader->setAllowStaleResources(false);
458             return false;
459         }
460 
461         m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
462         if (dragIsMove(innerFrame->selection(), dragData)) {
463             // NSTextView behavior is to always smart delete on moving a selection,
464             // but only to smart insert if the selection granularity is word granularity.
465             bool smartDelete = innerFrame->editor()->smartInsertDeleteEnabled();
466             bool smartInsert = smartDelete && innerFrame->selection()->granularity() == WordGranularity && dragData->canSmartReplace();
467             applyCommand(MoveSelectionCommand::create(fragment, dragCaret.base(), smartInsert, smartDelete));
468         } else {
469             if (setSelectionToDragCaret(innerFrame, dragCaret, range, point)) {
470                 ReplaceSelectionCommand::CommandOptions options = ReplaceSelectionCommand::SelectReplacement | ReplaceSelectionCommand::PreventNesting;
471                 if (dragData->canSmartReplace())
472                     options |= ReplaceSelectionCommand::SmartReplace;
473                 if (chosePlainText)
474                     options |= ReplaceSelectionCommand::MatchStyle;
475                 applyCommand(ReplaceSelectionCommand::create(m_documentUnderMouse.get(), fragment, options));
476             }
477         }
478     } else {
479         String text = dragData->asPlainText(innerFrame);
480         if (text.isEmpty() || !innerFrame->editor()->shouldInsertText(text, range.get(), EditorInsertActionDropped)) {
481             cachedResourceLoader->setAllowStaleResources(false);
482             return false;
483         }
484 
485         m_client->willPerformDragDestinationAction(DragDestinationActionEdit, dragData);
486         if (setSelectionToDragCaret(innerFrame, dragCaret, range, point))
487             applyCommand(ReplaceSelectionCommand::create(m_documentUnderMouse.get(), createFragmentFromText(range.get(), text),  ReplaceSelectionCommand::SelectReplacement | ReplaceSelectionCommand::MatchStyle | ReplaceSelectionCommand::PreventNesting));
488     }
489     cachedResourceLoader->setAllowStaleResources(false);
490 
491     return true;
492 }
493 
canProcessDrag(DragData * dragData)494 bool DragController::canProcessDrag(DragData* dragData)
495 {
496     ASSERT(dragData);
497 
498     if (!dragData->containsCompatibleContent())
499         return false;
500 
501     IntPoint point = m_page->mainFrame()->view()->windowToContents(dragData->clientPosition());
502     HitTestResult result = HitTestResult(point);
503     if (!m_page->mainFrame()->contentRenderer())
504         return false;
505 
506     result = m_page->mainFrame()->eventHandler()->hitTestResultAtPoint(point, true);
507 
508     if (!result.innerNonSharedNode())
509         return false;
510 
511     if (dragData->containsFiles() && asFileInput(result.innerNonSharedNode()))
512         return true;
513 
514     if (!result.innerNonSharedNode()->rendererIsEditable())
515         return false;
516 
517     if (m_didInitiateDrag && m_documentUnderMouse == m_dragInitiator && result.isSelected())
518         return false;
519 
520     return true;
521 }
522 
defaultOperationForDrag(DragOperation srcOpMask)523 static DragOperation defaultOperationForDrag(DragOperation srcOpMask)
524 {
525     // This is designed to match IE's operation fallback for the case where
526     // the page calls preventDefault() in a drag event but doesn't set dropEffect.
527     if (srcOpMask == DragOperationEvery)
528         return DragOperationCopy;
529     if (srcOpMask == DragOperationNone)
530         return DragOperationNone;
531     if (srcOpMask & DragOperationMove || srcOpMask & DragOperationGeneric)
532         return DragOperationMove;
533     if (srcOpMask & DragOperationCopy)
534         return DragOperationCopy;
535     if (srcOpMask & DragOperationLink)
536         return DragOperationLink;
537 
538     // FIXME: Does IE really return "generic" even if no operations were allowed by the source?
539     return DragOperationGeneric;
540 }
541 
tryDHTMLDrag(DragData * dragData,DragOperation & operation)542 bool DragController::tryDHTMLDrag(DragData* dragData, DragOperation& operation)
543 {
544     ASSERT(dragData);
545     ASSERT(m_documentUnderMouse);
546     RefPtr<Frame> mainFrame = m_page->mainFrame();
547     RefPtr<FrameView> viewProtector = mainFrame->view();
548     if (!viewProtector)
549         return false;
550 
551     ClipboardAccessPolicy policy = m_documentUnderMouse->securityOrigin()->isLocal() ? ClipboardReadable : ClipboardTypesReadable;
552     RefPtr<Clipboard> clipboard = Clipboard::create(policy, dragData, mainFrame.get());
553     DragOperation srcOpMask = dragData->draggingSourceOperationMask();
554     clipboard->setSourceOperation(srcOpMask);
555 
556     PlatformMouseEvent event = createMouseEvent(dragData);
557     if (!mainFrame->eventHandler()->updateDragAndDrop(event, clipboard.get())) {
558         clipboard->setAccessPolicy(ClipboardNumb);    // invalidate clipboard here for security
559         return false;
560     }
561 
562     operation = clipboard->destinationOperation();
563     if (clipboard->dropEffectIsUninitialized())
564         operation = defaultOperationForDrag(srcOpMask);
565     else if (!(srcOpMask & operation)) {
566         // The element picked an operation which is not supported by the source
567         operation = DragOperationNone;
568     }
569 
570     clipboard->setAccessPolicy(ClipboardNumb);    // invalidate clipboard here for security
571     return true;
572 }
573 
mayStartDragAtEventLocation(const Frame * frame,const IntPoint & framePos,Node * node)574 bool DragController::mayStartDragAtEventLocation(const Frame* frame, const IntPoint& framePos, Node* node)
575 {
576     ASSERT(frame);
577     ASSERT(frame->settings());
578 
579     if (!frame->view() || !frame->contentRenderer())
580         return false;
581 
582     HitTestResult mouseDownTarget = HitTestResult(framePos);
583 
584     mouseDownTarget = frame->eventHandler()->hitTestResultAtPoint(framePos, true);
585     if (node)
586         mouseDownTarget.setInnerNonSharedNode(node);
587 
588     if (mouseDownTarget.image()
589         && !mouseDownTarget.absoluteImageURL().isEmpty()
590         && frame->settings()->loadsImagesAutomatically()
591         && m_dragSourceAction & DragSourceActionImage)
592         return true;
593 
594     if (!mouseDownTarget.absoluteLinkURL().isEmpty()
595         && m_dragSourceAction & DragSourceActionLink
596         && mouseDownTarget.isLiveLink()
597         && mouseDownTarget.URLElement()->renderer() && mouseDownTarget.URLElement()->renderer()->style()->userDrag() != DRAG_NONE)
598         return true;
599 
600     if (mouseDownTarget.isSelected()
601         && m_dragSourceAction & DragSourceActionSelection)
602         return true;
603 
604     return false;
605 }
606 
getCachedImage(Element * element)607 static CachedImage* getCachedImage(Element* element)
608 {
609     ASSERT(element);
610     RenderObject* renderer = element->renderer();
611     if (!renderer || !renderer->isImage())
612         return 0;
613     RenderImage* image = toRenderImage(renderer);
614     return image->cachedImage();
615 }
616 
getImage(Element * element)617 static Image* getImage(Element* element)
618 {
619     ASSERT(element);
620     CachedImage* cachedImage = getCachedImage(element);
621     return (cachedImage && !cachedImage->errorOccurred()) ?
622         cachedImage->image() : 0;
623 }
624 
prepareClipboardForImageDrag(Frame * src,Clipboard * clipboard,Element * node,const KURL & linkURL,const KURL & imageURL,const String & label)625 static void prepareClipboardForImageDrag(Frame* src, Clipboard* clipboard, Element* node, const KURL& linkURL, const KURL& imageURL, const String& label)
626 {
627     RefPtr<Range> range = src->document()->createRange();
628     ExceptionCode ec = 0;
629     range->selectNode(node, ec);
630     ASSERT(!ec);
631     src->selection()->setSelection(VisibleSelection(range.get(), DOWNSTREAM));
632     clipboard->declareAndWriteDragImage(node, !linkURL.isEmpty() ? linkURL : imageURL, label, src);
633 }
634 
dragLocForDHTMLDrag(const IntPoint & mouseDraggedPoint,const IntPoint & dragOrigin,const IntPoint & dragImageOffset,bool isLinkImage)635 static IntPoint dragLocForDHTMLDrag(const IntPoint& mouseDraggedPoint, const IntPoint& dragOrigin, const IntPoint& dragImageOffset, bool isLinkImage)
636 {
637     // dragImageOffset is the cursor position relative to the lower-left corner of the image.
638 #if PLATFORM(MAC)
639     // We add in the Y dimension because we are a flipped view, so adding moves the image down.
640     const int yOffset = dragImageOffset.y();
641 #else
642     const int yOffset = -dragImageOffset.y();
643 #endif
644 
645     if (isLinkImage)
646         return IntPoint(mouseDraggedPoint.x() - dragImageOffset.x(), mouseDraggedPoint.y() + yOffset);
647 
648     return IntPoint(dragOrigin.x() - dragImageOffset.x(), dragOrigin.y() + yOffset);
649 }
650 
dragLocForSelectionDrag(Frame * src)651 static IntPoint dragLocForSelectionDrag(Frame* src)
652 {
653     IntRect draggingRect = enclosingIntRect(src->selection()->bounds());
654     int xpos = draggingRect.maxX();
655     xpos = draggingRect.x() < xpos ? draggingRect.x() : xpos;
656     int ypos = draggingRect.maxY();
657 #if PLATFORM(MAC)
658     // Deal with flipped coordinates on Mac
659     ypos = draggingRect.y() > ypos ? draggingRect.y() : ypos;
660 #else
661     ypos = draggingRect.y() < ypos ? draggingRect.y() : ypos;
662 #endif
663     return IntPoint(xpos, ypos);
664 }
665 
startDrag(Frame * src,Clipboard * clipboard,DragOperation srcOp,const PlatformMouseEvent & dragEvent,const IntPoint & dragOrigin,bool isDHTMLDrag)666 bool DragController::startDrag(Frame* src, Clipboard* clipboard, DragOperation srcOp, const PlatformMouseEvent& dragEvent, const IntPoint& dragOrigin, bool isDHTMLDrag)
667 {
668     ASSERT(src);
669     ASSERT(clipboard);
670 
671     if (!src->view() || !src->contentRenderer())
672         return false;
673 
674     HitTestResult dragSource = HitTestResult(dragOrigin);
675     dragSource = src->eventHandler()->hitTestResultAtPoint(dragOrigin, true);
676     KURL linkURL = dragSource.absoluteLinkURL();
677     KURL imageURL = dragSource.absoluteImageURL();
678     bool isSelected = dragSource.isSelected();
679 
680     IntPoint mouseDraggedPoint = src->view()->windowToContents(dragEvent.pos());
681 
682     m_draggingImageURL = KURL();
683     m_sourceDragOperation = srcOp;
684 
685     DragImageRef dragImage = 0;
686     IntPoint dragLoc(0, 0);
687     IntPoint dragImageOffset(0, 0);
688 
689     if (isDHTMLDrag)
690         dragImage = clipboard->createDragImage(dragImageOffset);
691     else {
692         // This drag operation is not a DHTML drag and may go outside the WebView.
693         // We provide a default set of allowed drag operations that follows from:
694         // http://trac.webkit.org/browser/trunk/WebKit/mac/WebView/WebHTMLView.mm?rev=48526#L3430
695         m_sourceDragOperation = (DragOperation)(DragOperationGeneric | DragOperationCopy);
696     }
697 
698     // We allow DHTML/JS to set the drag image, even if its a link, image or text we're dragging.
699     // This is in the spirit of the IE API, which allows overriding of pasteboard data and DragOp.
700     if (dragImage) {
701         dragLoc = dragLocForDHTMLDrag(mouseDraggedPoint, dragOrigin, dragImageOffset, !linkURL.isEmpty());
702         m_dragOffset = dragImageOffset;
703     }
704 
705     bool startedDrag = true; // optimism - we almost always manage to start the drag
706 
707     Node* node = dragSource.innerNonSharedNode();
708 
709     Image* image = getImage(static_cast<Element*>(node));
710     if (!imageURL.isEmpty() && node && node->isElementNode() && image
711             && (m_dragSourceAction & DragSourceActionImage)) {
712         // We shouldn't be starting a drag for an image that can't provide an extension.
713         // This is an early detection for problems encountered later upon drop.
714         ASSERT(!image->filenameExtension().isEmpty());
715         Element* element = static_cast<Element*>(node);
716         if (!clipboard->hasData()) {
717             m_draggingImageURL = imageURL;
718             prepareClipboardForImageDrag(src, clipboard, element, linkURL, imageURL, dragSource.altDisplayString());
719         }
720 
721         m_client->willPerformDragSourceAction(DragSourceActionImage, dragOrigin, clipboard);
722 
723         if (!dragImage) {
724             IntRect imageRect = dragSource.imageRect();
725             imageRect.setLocation(m_page->mainFrame()->view()->windowToContents(src->view()->contentsToWindow(imageRect.location())));
726             doImageDrag(element, dragOrigin, dragSource.imageRect(), clipboard, src, m_dragOffset);
727         } else
728             // DHTML defined drag image
729             doSystemDrag(dragImage, dragLoc, dragOrigin, clipboard, src, false);
730 
731     } else if (!linkURL.isEmpty() && (m_dragSourceAction & DragSourceActionLink)) {
732         if (!clipboard->hasData())
733             // Simplify whitespace so the title put on the clipboard resembles what the user sees
734             // on the web page. This includes replacing newlines with spaces.
735             clipboard->writeURL(linkURL, dragSource.textContent().simplifyWhiteSpace(), src);
736 
737         if (src->selection()->isCaret() && src->selection()->isContentEditable()) {
738             // a user can initiate a drag on a link without having any text
739             // selected.  In this case, we should expand the selection to
740             // the enclosing anchor element
741             Position pos = src->selection()->base();
742             Node* node = enclosingAnchorElement(pos);
743             if (node)
744                 src->selection()->setSelection(VisibleSelection::selectionFromContentsOfNode(node));
745         }
746 
747         m_client->willPerformDragSourceAction(DragSourceActionLink, dragOrigin, clipboard);
748         if (!dragImage) {
749             dragImage = createDragImageForLink(linkURL, dragSource.textContent(), src);
750             IntSize size = dragImageSize(dragImage);
751             m_dragOffset = IntPoint(-size.width() / 2, -LinkDragBorderInset);
752             dragLoc = IntPoint(mouseDraggedPoint.x() + m_dragOffset.x(), mouseDraggedPoint.y() + m_dragOffset.y());
753         }
754         doSystemDrag(dragImage, dragLoc, mouseDraggedPoint, clipboard, src, true);
755     } else if (isSelected && (m_dragSourceAction & DragSourceActionSelection)) {
756         if (!clipboard->hasData()) {
757             if (isNodeInTextFormControl(src->selection()->start().deprecatedNode()))
758                 clipboard->writePlainText(src->editor()->selectedText());
759             else {
760                 RefPtr<Range> selectionRange = src->selection()->toNormalizedRange();
761                 ASSERT(selectionRange);
762 
763                 clipboard->writeRange(selectionRange.get(), src);
764             }
765         }
766         m_client->willPerformDragSourceAction(DragSourceActionSelection, dragOrigin, clipboard);
767         if (!dragImage) {
768             dragImage = createDragImageForSelection(src);
769             dragLoc = dragLocForSelectionDrag(src);
770             m_dragOffset = IntPoint((int)(dragOrigin.x() - dragLoc.x()), (int)(dragOrigin.y() - dragLoc.y()));
771         }
772         doSystemDrag(dragImage, dragLoc, dragOrigin, clipboard, src, false);
773     } else if (isDHTMLDrag) {
774         ASSERT(m_dragSourceAction & DragSourceActionDHTML);
775         m_client->willPerformDragSourceAction(DragSourceActionDHTML, dragOrigin, clipboard);
776         doSystemDrag(dragImage, dragLoc, dragOrigin, clipboard, src, false);
777     } else {
778         // Only way I know to get here is if to get here is if the original element clicked on in the mousedown is no longer
779         // under the mousedown point, so linkURL, imageURL and isSelected are all false/empty.
780         startedDrag = false;
781     }
782 
783     if (dragImage)
784         deleteDragImage(dragImage);
785     return startedDrag;
786 }
787 
doImageDrag(Element * element,const IntPoint & dragOrigin,const IntRect & rect,Clipboard * clipboard,Frame * frame,IntPoint & dragImageOffset)788 void DragController::doImageDrag(Element* element, const IntPoint& dragOrigin, const IntRect& rect, Clipboard* clipboard, Frame* frame, IntPoint& dragImageOffset)
789 {
790     IntPoint mouseDownPoint = dragOrigin;
791     DragImageRef dragImage;
792     IntPoint origin;
793 
794     Image* image = getImage(element);
795     if (image && image->size().height() * image->size().width() <= MaxOriginalImageArea
796         && (dragImage = createDragImageFromImage(image))) {
797         IntSize originalSize = rect.size();
798         origin = rect.location();
799 
800         dragImage = fitDragImageToMaxSize(dragImage, rect.size(), maxDragImageSize());
801         dragImage = dissolveDragImageToFraction(dragImage, DragImageAlpha);
802         IntSize newSize = dragImageSize(dragImage);
803 
804         // Properly orient the drag image and orient it differently if it's smaller than the original
805         float scale = newSize.width() / (float)originalSize.width();
806         float dx = origin.x() - mouseDownPoint.x();
807         dx *= scale;
808         origin.setX((int)(dx + 0.5));
809 #if PLATFORM(MAC)
810         //Compensate for accursed flipped coordinates in cocoa
811         origin.setY(origin.y() + originalSize.height());
812 #endif
813         float dy = origin.y() - mouseDownPoint.y();
814         dy *= scale;
815         origin.setY((int)(dy + 0.5));
816     } else {
817         dragImage = createDragImageIconForCachedImage(getCachedImage(element));
818         if (dragImage)
819             origin = IntPoint(DragIconRightInset - dragImageSize(dragImage).width(), DragIconBottomInset);
820     }
821 
822     dragImageOffset.setX(mouseDownPoint.x() + origin.x());
823     dragImageOffset.setY(mouseDownPoint.y() + origin.y());
824     doSystemDrag(dragImage, dragImageOffset, dragOrigin, clipboard, frame, false);
825 
826     deleteDragImage(dragImage);
827 }
828 
doSystemDrag(DragImageRef image,const IntPoint & dragLoc,const IntPoint & eventPos,Clipboard * clipboard,Frame * frame,bool forLink)829 void DragController::doSystemDrag(DragImageRef image, const IntPoint& dragLoc, const IntPoint& eventPos, Clipboard* clipboard, Frame* frame, bool forLink)
830 {
831     m_didInitiateDrag = true;
832     m_dragInitiator = frame->document();
833     // Protect this frame and view, as a load may occur mid drag and attempt to unload this frame
834     RefPtr<Frame> frameProtector = m_page->mainFrame();
835     RefPtr<FrameView> viewProtector = frameProtector->view();
836     m_client->startDrag(image, viewProtector->windowToContents(frame->view()->contentsToWindow(dragLoc)),
837         viewProtector->windowToContents(frame->view()->contentsToWindow(eventPos)), clipboard, frameProtector.get(), forLink);
838 
839     cleanupAfterSystemDrag();
840 }
841 
842 // Manual drag caret manipulation
placeDragCaret(const IntPoint & windowPoint)843 void DragController::placeDragCaret(const IntPoint& windowPoint)
844 {
845     mouseMovedIntoDocument(m_page->mainFrame()->documentAtPoint(windowPoint));
846     if (!m_documentUnderMouse)
847         return;
848     Frame* frame = m_documentUnderMouse->frame();
849     FrameView* frameView = frame->view();
850     if (!frameView)
851         return;
852     IntPoint framePoint = frameView->windowToContents(windowPoint);
853     VisibleSelection dragCaret(frame->visiblePositionForPoint(framePoint));
854     m_page->dragCaretController()->setSelection(dragCaret);
855 }
856 
857 } // namespace WebCore
858 
859 #endif // ENABLE(DRAG_SUPPORT)
860