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      1 /*
      2  * Copyright (C) 2012 Google 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  *
      8  * 1.  Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  * 2.  Redistributions in binary form must reproduce the above copyright
     11  *     notice, this list of conditions and the following disclaimer in the
     12  *     documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     17  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     21  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "core/html/HTMLDialogElement.h"
     28 
     29 #include "bindings/core/v8/ExceptionState.h"
     30 #include "core/accessibility/AXObjectCache.h"
     31 #include "core/dom/ExceptionCode.h"
     32 #include "core/dom/NodeTraversal.h"
     33 #include "core/events/Event.h"
     34 #include "core/frame/UseCounter.h"
     35 #include "core/html/HTMLFormControlElement.h"
     36 #include "core/frame/FrameView.h"
     37 #include "core/rendering/RenderBlock.h"
     38 #include "core/rendering/style/RenderStyle.h"
     39 
     40 namespace blink {
     41 
     42 using namespace HTMLNames;
     43 
     44 // This function chooses the focused element when showModal() is invoked, as described in the spec for showModal().
     45 static void setFocusForModalDialog(HTMLDialogElement* dialog)
     46 {
     47     Element* focusableDescendant = 0;
     48     Node* next = 0;
     49     for (Node* node = dialog->firstChild(); node; node = next) {
     50         if (isHTMLDialogElement(*node))
     51             next = NodeTraversal::nextSkippingChildren(*node, dialog);
     52         else
     53             next = NodeTraversal::next(*node, dialog);
     54 
     55         if (!node->isElementNode())
     56             continue;
     57         Element* element = toElement(node);
     58         if (element->isFormControlElement()) {
     59             HTMLFormControlElement* control = toHTMLFormControlElement(node);
     60             if (control->isAutofocusable()) {
     61                 control->focus();
     62                 return;
     63             }
     64         }
     65         if (!focusableDescendant && element->isFocusable())
     66             focusableDescendant = element;
     67     }
     68 
     69     if (focusableDescendant) {
     70         focusableDescendant->focus();
     71         return;
     72     }
     73 
     74     if (dialog->isFocusable()) {
     75         dialog->focus();
     76         return;
     77     }
     78 
     79     dialog->document().setFocusedElement(nullptr);
     80 }
     81 
     82 static void inertSubtreesChanged(Document& document)
     83 {
     84     // When a modal dialog opens or closes, nodes all over the accessibility
     85     // tree can change inertness which means they must be added or removed from
     86     // the tree. The most foolproof way is to clear the entire tree and rebuild
     87     // it, though a more clever way is probably possible.
     88     Document& topDocument = document.topDocument();
     89     topDocument.clearAXObjectCache();
     90     if (AXObjectCache* cache = topDocument.axObjectCache())
     91         cache->childrenChanged(cache->getOrCreate(&topDocument));
     92 }
     93 
     94 inline HTMLDialogElement::HTMLDialogElement(Document& document)
     95     : HTMLElement(dialogTag, document)
     96     , m_centeringMode(NotCentered)
     97     , m_centeredPosition(0)
     98     , m_returnValue("")
     99 {
    100     UseCounter::count(document, UseCounter::DialogElement);
    101 }
    102 
    103 DEFINE_NODE_FACTORY(HTMLDialogElement)
    104 
    105 void HTMLDialogElement::close(const String& returnValue, ExceptionState& exceptionState)
    106 {
    107     if (!fastHasAttribute(openAttr)) {
    108         exceptionState.throwDOMException(InvalidStateError, "The element does not have an 'open' attribute, and therefore cannot be closed.");
    109         return;
    110     }
    111     closeDialog(returnValue);
    112 }
    113 
    114 void HTMLDialogElement::closeDialog(const String& returnValue)
    115 {
    116     if (!fastHasAttribute(openAttr))
    117         return;
    118     setBooleanAttribute(openAttr, false);
    119 
    120     HTMLDialogElement* activeModalDialog = document().activeModalDialog();
    121     document().removeFromTopLayer(this);
    122     if (activeModalDialog == this)
    123         inertSubtreesChanged(document());
    124 
    125     if (!returnValue.isNull())
    126         m_returnValue = returnValue;
    127 
    128     dispatchScopedEvent(Event::create(EventTypeNames::close));
    129 }
    130 
    131 void HTMLDialogElement::forceLayoutForCentering()
    132 {
    133     m_centeringMode = NeedsCentering;
    134     document().updateLayoutIgnorePendingStylesheets();
    135     if (m_centeringMode == NeedsCentering)
    136         setNotCentered();
    137 }
    138 
    139 void HTMLDialogElement::show()
    140 {
    141     if (fastHasAttribute(openAttr))
    142         return;
    143     setBooleanAttribute(openAttr, true);
    144 }
    145 
    146 void HTMLDialogElement::showModal(ExceptionState& exceptionState)
    147 {
    148     if (fastHasAttribute(openAttr)) {
    149         exceptionState.throwDOMException(InvalidStateError, "The element already has an 'open' attribute, and therefore cannot be opened modally.");
    150         return;
    151     }
    152     if (!inDocument()) {
    153         exceptionState.throwDOMException(InvalidStateError, "The element is not in a Document.");
    154         return;
    155     }
    156 
    157     document().addToTopLayer(this);
    158     setBooleanAttribute(openAttr, true);
    159 
    160     // Throw away the AX cache first, so the subsequent steps don't have a chance of queuing up
    161     // AX events on objects that would be invalidated when the cache is thrown away.
    162     inertSubtreesChanged(document());
    163 
    164     forceLayoutForCentering();
    165     setFocusForModalDialog(this);
    166 }
    167 
    168 void HTMLDialogElement::removedFrom(ContainerNode* insertionPoint)
    169 {
    170     HTMLElement::removedFrom(insertionPoint);
    171     setNotCentered();
    172     // FIXME: We should call inertSubtreesChanged() here.
    173 }
    174 
    175 void HTMLDialogElement::setCentered(LayoutUnit centeredPosition)
    176 {
    177     ASSERT(m_centeringMode == NeedsCentering);
    178     m_centeredPosition = centeredPosition;
    179     m_centeringMode = Centered;
    180 }
    181 
    182 void HTMLDialogElement::setNotCentered()
    183 {
    184     m_centeringMode = NotCentered;
    185 }
    186 
    187 bool HTMLDialogElement::isPresentationAttribute(const QualifiedName& name) const
    188 {
    189     // FIXME: Workaround for <https://bugs.webkit.org/show_bug.cgi?id=91058>: modifying an attribute for which there is an attribute selector
    190     // in html.css sometimes does not trigger a style recalc.
    191     if (name == openAttr)
    192         return true;
    193 
    194     return HTMLElement::isPresentationAttribute(name);
    195 }
    196 
    197 void HTMLDialogElement::defaultEventHandler(Event* event)
    198 {
    199     if (event->type() == EventTypeNames::cancel) {
    200         closeDialog();
    201         event->setDefaultHandled();
    202         return;
    203     }
    204     HTMLElement::defaultEventHandler(event);
    205 }
    206 
    207 } // namespace blink
    208