summaryrefslogtreecommitdiff
path: root/dom/html/HTMLLabelElement.cpp
blob: d1c037336eeb002032f1785fcef898d72144ab4b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * Implementation of HTML <label> elements.
 */
#include "HTMLLabelElement.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/dom/HTMLLabelElementBinding.h"
#include "nsFocusManager.h"
#include "nsIDOMMouseEvent.h"
#include "nsQueryObject.h"
#include "mozilla/dom/ShadowRoot.h"

// construction, destruction

NS_IMPL_NS_NEW_HTML_ELEMENT(Label)

namespace mozilla {
namespace dom {

HTMLLabelElement::~HTMLLabelElement()
{
}

JSObject*
HTMLLabelElement::WrapNode(JSContext *aCx, JS::Handle<JSObject*> aGivenProto)
{
  return HTMLLabelElementBinding::Wrap(aCx, this, aGivenProto);
}

// nsISupports

NS_IMPL_ISUPPORTS_INHERITED(HTMLLabelElement, nsGenericHTMLElement,
                            nsIDOMHTMLLabelElement)

// nsIDOMHTMLLabelElement

NS_IMPL_ELEMENT_CLONE(HTMLLabelElement)

NS_IMETHODIMP
HTMLLabelElement::GetForm(nsIDOMHTMLFormElement** aForm)
{
  RefPtr<nsIDOMHTMLFormElement> form = GetForm();
  form.forget(aForm);
  return NS_OK;
}

NS_IMETHODIMP
HTMLLabelElement::GetControl(nsIDOMHTMLElement** aElement)
{
  nsCOMPtr<nsIDOMHTMLElement> element = do_QueryObject(GetLabeledElement());
  element.forget(aElement);
  return NS_OK;
}

NS_IMETHODIMP
HTMLLabelElement::SetHtmlFor(const nsAString& aHtmlFor)
{
  ErrorResult rv;
  SetHtmlFor(aHtmlFor, rv);
  return rv.StealNSResult();
}

NS_IMETHODIMP
HTMLLabelElement::GetHtmlFor(nsAString& aHtmlFor)
{
  nsString htmlFor;
  GetHtmlFor(htmlFor);
  aHtmlFor = htmlFor;
  return NS_OK;
}

HTMLFormElement*
HTMLLabelElement::GetForm() const
{
  nsGenericHTMLElement* control = GetControl();
  if (!control) {
    return nullptr;
  }

  // Not all labeled things have a form association.  Stick to the ones that do.
  nsCOMPtr<nsIFormControl> formControl = do_QueryObject(control);
  if (!formControl) {
    return nullptr;
  }

  return static_cast<HTMLFormElement*>(formControl->GetFormElement());
}

void
HTMLLabelElement::Focus(ErrorResult& aError)
{
  // retarget the focus method at the for content
  nsIFocusManager* fm = nsFocusManager::GetFocusManager();
  if (fm) {
    nsCOMPtr<nsIDOMElement> elem = do_QueryObject(GetLabeledElement());
    if (elem)
      fm->SetFocus(elem, 0);
  }
}

static bool
InInteractiveHTMLContent(nsIContent* aContent, nsIContent* aStop)
{
  nsIContent* content = aContent;
  while (content && content != aStop) {
    if (content->IsElement() &&
        content->AsElement()->IsInteractiveHTMLContent(true)) {
      return true;
    }
    content = content->GetParent();
  }
  return false;
}

nsresult
HTMLLabelElement::PostHandleEvent(EventChainPostVisitor& aVisitor)
{
  WidgetMouseEvent* mouseEvent = aVisitor.mEvent->AsMouseEvent();
  if (mHandlingEvent ||
      (!(mouseEvent && mouseEvent->IsLeftClickEvent()) &&
       aVisitor.mEvent->mMessage != eMouseDown) ||
      aVisitor.mEventStatus == nsEventStatus_eConsumeNoDefault ||
      !aVisitor.mPresContext ||
      // Don't handle the event if it's already been handled by another label
      aVisitor.mEvent->mFlags.mMultipleActionsPrevented) {
    return NS_OK;
  }

  nsCOMPtr<nsIContent> target = do_QueryInterface(aVisitor.mEvent->mTarget);
  if (InInteractiveHTMLContent(target, this)) {
    return NS_OK;
  }

  // Strong ref because event dispatch is going to happen.
  RefPtr<Element> content = GetLabeledElement();

  if (content) {
    mHandlingEvent = true;
    switch (aVisitor.mEvent->mMessage) {
      case eMouseDown:
        if (mouseEvent->button == WidgetMouseEvent::eLeftButton) {
          // We reset the mouse-down point on every event because there is
          // no guarantee we will reach the eMouseClick code below.
          LayoutDeviceIntPoint* curPoint =
            new LayoutDeviceIntPoint(mouseEvent->mRefPoint);
          SetProperty(nsGkAtoms::labelMouseDownPtProperty,
                      static_cast<void*>(curPoint),
                      nsINode::DeleteProperty<LayoutDeviceIntPoint>);
        }
        break;

      case eMouseClick:
        if (mouseEvent->IsLeftClickEvent()) {
          LayoutDeviceIntPoint* mouseDownPoint =
            static_cast<LayoutDeviceIntPoint*>(
              GetProperty(nsGkAtoms::labelMouseDownPtProperty));

          bool dragSelect = false;
          if (mouseDownPoint) {
            LayoutDeviceIntPoint dragDistance = *mouseDownPoint;
            DeleteProperty(nsGkAtoms::labelMouseDownPtProperty);

            dragDistance -= mouseEvent->mRefPoint;
            const int CLICK_DISTANCE = 2;
            dragSelect = dragDistance.x > CLICK_DISTANCE ||
                         dragDistance.x < -CLICK_DISTANCE ||
                         dragDistance.y > CLICK_DISTANCE ||
                         dragDistance.y < -CLICK_DISTANCE;
          }
          // Don't click the for-content if we did drag-select text or if we
          // have a kbd modifier (which adjusts a selection).
          if (dragSelect || mouseEvent->IsShift() || mouseEvent->IsControl() ||
              mouseEvent->IsAlt() || mouseEvent->IsMeta()) {
            break;
          }
          // Only set focus on the first click of multiple clicks to prevent
          // to prevent immediate de-focus.
          if (mouseEvent->mClickCount <= 1) {
            nsIFocusManager* fm = nsFocusManager::GetFocusManager();
            if (fm) {
              // Use FLAG_BYMOVEFOCUS here so that the label is scrolled to.
              // Also, within HTMLInputElement::PostHandleEvent, inputs will
              // be selected only when focused via a key or when the navigation
              // flag is used and we want to select the text on label clicks as
              // well.
              // If the label has been clicked by the user, we also want to
              // pass FLAG_BYMOUSE so that we get correct focus ring behavior,
              // but we don't want to pass FLAG_BYMOUSE if this click event was
              // caused by the user pressing an accesskey.
              nsCOMPtr<nsIDOMElement> elem = do_QueryInterface(content);
              bool byMouse = (mouseEvent->inputSource != nsIDOMMouseEvent::MOZ_SOURCE_KEYBOARD);
              bool byTouch = (mouseEvent->inputSource == nsIDOMMouseEvent::MOZ_SOURCE_TOUCH);
              fm->SetFocus(elem, nsIFocusManager::FLAG_BYMOVEFOCUS |
                                 (byMouse ? nsIFocusManager::FLAG_BYMOUSE : 0) |
                                 (byTouch ? nsIFocusManager::FLAG_BYTOUCH : 0));
            }
          }
          // Dispatch a new click event to |content|
          //    (For compatibility with IE, we do only left click.  If
          //    we wanted to interpret the HTML spec very narrowly, we
          //    would do nothing.  If we wanted to do something
          //    sensible, we might send more events through like
          //    this.)  See bug 7554, bug 49897, and bug 96813.
          nsEventStatus status = aVisitor.mEventStatus;
          // Ok to use aVisitor.mEvent as parameter because DispatchClickEvent
          // will actually create a new event.
          EventFlags eventFlags;
          eventFlags.mMultipleActionsPrevented = true;
          DispatchClickEvent(aVisitor.mPresContext, mouseEvent,
                             content, false, &eventFlags, &status);
          // Do we care about the status this returned?  I don't think we do...
          // Don't run another <label> off of this click
          mouseEvent->mFlags.mMultipleActionsPrevented = true;
        }
        break;

      default:
        break;
    }
    mHandlingEvent = false;
  }
  return NS_OK;
}

bool
HTMLLabelElement::PerformAccesskey(bool aKeyCausesActivation,
                                   bool aIsTrustedEvent)
{
  if (!aKeyCausesActivation) {
    RefPtr<Element> element = GetLabeledElement();
    if (element) {
      return element->PerformAccesskey(aKeyCausesActivation, aIsTrustedEvent);
    }
  } else {
    nsPresContext *presContext = GetPresContext(eForUncomposedDoc);
    if (!presContext) {
      return false;
    }

    // Click on it if the users prefs indicate to do so.
    WidgetMouseEvent event(aIsTrustedEvent, eMouseClick,
                           nullptr, WidgetMouseEvent::eReal);
    event.inputSource = nsIDOMMouseEvent::MOZ_SOURCE_KEYBOARD;

    nsAutoPopupStatePusher popupStatePusher(aIsTrustedEvent ?
                                            openAllowed : openAbused);

    EventDispatcher::Dispatch(static_cast<nsIContent*>(this), presContext,
                              &event);
  }

  return aKeyCausesActivation;
}

nsGenericHTMLElement*
HTMLLabelElement::GetLabeledElement() const
{
  nsAutoString elementId;

  if (!GetAttr(kNameSpaceID_None, nsGkAtoms::_for, elementId)) {
    // No @for, so we are a label for our first form control element.
    // Do a depth-first traversal to look for the first form control element.
    return GetFirstLabelableDescendant();
  }

  // We have a @for. The id has to be linked to an element in the same tree
  // and this element should be a labelable form control.
  nsINode* root = SubtreeRoot();
  ShadowRoot* shadow = ShadowRoot::FromNode(root);
  Element* element = nullptr;

  if (shadow) {
    element = shadow->GetElementById(elementId);
  } else {
    nsIDocument* doc = GetUncomposedDoc();
    if (doc) {
      element = doc->GetElementById(elementId);
    } else {
      element = nsContentUtils::MatchElementId(root->AsContent(), elementId);
    }
  }

  if (element && element->IsLabelable()) {
    return static_cast<nsGenericHTMLElement*>(element);
  }

  return nullptr;
}

nsGenericHTMLElement*
HTMLLabelElement::GetFirstLabelableDescendant() const
{
  for (nsIContent* cur = nsINode::GetFirstChild(); cur;
       cur = cur->GetNextNode(this)) {
    Element* element = cur->IsElement() ? cur->AsElement() : nullptr;
    if (element && element->IsLabelable()) {
      return static_cast<nsGenericHTMLElement*>(element);
    }
  }

  return nullptr;
}

} // namespace dom
} // namespace mozilla