layout/xul/nsScrollbarButtonFrame.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 //
   8 // Eric Vaughan
   9 // Netscape Communications
  10 //
  11 // See documentation in associated header file
  12 //
  13
  14 #include "nsScrollbarButtonFrame.h"
  15 #include "nsPresContext.h"
  16 #include "nsIContent.h"
  17 #include "nsCOMPtr.h"
  18 #include "nsNameSpaceManager.h"
  19 #include "nsGkAtoms.h"
  20 #include "nsLayoutUtils.h"
  21 #include "nsSliderFrame.h"
  22 #include "nsScrollbarFrame.h"
  23 #include "nsIScrollbarMediator.h"
  24 #include "nsRepeatService.h"
  25 #include "mozilla/LookAndFeel.h"
  26 #include "mozilla/MouseEvents.h"
  27 #include "mozilla/PresShell.h"
  28 #include "mozilla/Telemetry.h"
  29
  30 using namespace mozilla;
  31
  32 //
  33 // NS_NewToolbarFrame
  34 //
  35 // Creates a new Toolbar frame and returns it
  36 //
  37 nsIFrame* NS_NewScrollbarButtonFrame(PresShell* aPresShell,
  38                                      ComputedStyle* aStyle) {
  39   return new (aPresShell)
  40       nsScrollbarButtonFrame(aStyle, aPresShell->GetPresContext());
  41 }
  42
  43 NS_IMPL_FRAMEARENA_HELPERS(nsScrollbarButtonFrame)
  44
  45 nsresult nsScrollbarButtonFrame::HandleEvent(nsPresContext* aPresContext,
  46                                              WidgetGUIEvent* aEvent,
  47                                              nsEventStatus* aEventStatus) {
  48   NS_ENSURE_ARG_POINTER(aEventStatus);
  49
  50   // If a web page calls event.preventDefault() we still want to
  51   // scroll when scroll arrow is clicked. See bug 511075.
  52   if (!mContent->IsInNativeAnonymousSubtree() &&
  53       nsEventStatus_eConsumeNoDefault == *aEventStatus) {
  54     return NS_OK;
  55   }
  56
  57   switch (aEvent->mMessage) {
  58     case eMouseDown:
  59       mCursorOnThis = true;
  60       // if we didn't handle the press ourselves, pass it on to the superclass
  61       if (HandleButtonPress(aPresContext, aEvent, aEventStatus)) {
  62         return NS_OK;
  63       }
  64       break;
  65     case eMouseUp:
  66       HandleRelease(aPresContext, aEvent, aEventStatus);
  67       break;
  68     case eMouseOut:
  69       mCursorOnThis = false;
  70       break;
  71     case eMouseMove: {
  72       nsPoint cursor = nsLayoutUtils::GetEventCoordinatesRelativeTo(
  73           aEvent, RelativeTo{this});
  74       nsRect frameRect(nsPoint(0, 0), GetSize());
  75       mCursorOnThis = frameRect.Contains(cursor);
  76       break;
  77     }
  78     default:
  79       break;
  80   }
  81
  82   return nsBoxFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
  83 }
  84
  85 bool nsScrollbarButtonFrame::HandleButtonPress(nsPresContext* aPresContext,
  86                                                WidgetGUIEvent* aEvent,
  87                                                nsEventStatus* aEventStatus) {
  88   // Get the desired action for the scrollbar button.
  89   LookAndFeel::IntID tmpAction;
  90   uint16_t button = aEvent->AsMouseEvent()->mButton;
  91   if (button == MouseButton::ePrimary) {
  92     tmpAction = LookAndFeel::IntID::ScrollButtonLeftMouseButtonAction;
  93   } else if (button == MouseButton::eMiddle) {
  94     tmpAction = LookAndFeel::IntID::ScrollButtonMiddleMouseButtonAction;
  95   } else if (button == MouseButton::eSecondary) {
  96     tmpAction = LookAndFeel::IntID::ScrollButtonRightMouseButtonAction;
  97   } else {
  98     return false;
  99   }
 100
 101   // Get the button action metric from the pres. shell.
 102   int32_t pressedButtonAction;
 103   if (NS_FAILED(LookAndFeel::GetInt(tmpAction, &pressedButtonAction))) {
 104     return false;
 105   }
 106
 107   // get the scrollbar control
 108   nsIFrame* scrollbar;
 109   GetParentWithTag(nsGkAtoms::scrollbar, this, scrollbar);
 110
 111   if (scrollbar == nullptr) return false;
 112
 113   static dom::Element::AttrValuesArray strings[] = {
 114       nsGkAtoms::increment, nsGkAtoms::decrement, nullptr};
 115   int32_t index = mContent->AsElement()->FindAttrValueIn(
 116       kNameSpaceID_None, nsGkAtoms::type, strings, eCaseMatters);
 117   int32_t direction;
 118   if (index == 0)
 119     direction = 1;
 120   else if (index == 1)
 121     direction = -1;
 122   else
 123     return false;
 124
 125   bool repeat = pressedButtonAction != 2;
 126   // set this attribute so we can style it later
 127   AutoWeakFrame weakFrame(this);
 128   mContent->AsElement()->SetAttr(kNameSpaceID_None, nsGkAtoms::active,
 129                                  u"true"_ns, true);
 130
 131   PresShell::SetCapturingContent(mContent, CaptureFlags::IgnoreAllowedState);
 132
 133   if (!weakFrame.IsAlive()) {
 134     return false;
 135   }
 136
 137   if (nsScrollbarFrame* sb = do_QueryFrame(scrollbar)) {
 138     nsIScrollbarMediator* m = sb->GetScrollbarMediator();
 139     switch (pressedButtonAction) {
 140       case 0:
 141         sb->SetIncrementToLine(direction);
 142         if (m) {
 143           m->ScrollByLine(sb, direction, ScrollSnapFlags::IntendedDirection);
 144         }
 145         break;
 146       case 1:
 147         sb->SetIncrementToPage(direction);
 148         if (m) {
 149           m->ScrollByPage(sb, direction,
 150                           ScrollSnapFlags::IntendedDirection |
 151                               ScrollSnapFlags::IntendedEndPosition);
 152         }
 153         break;
 154       case 2:
 155         sb->SetIncrementToWhole(direction);
 156         if (m) {
 157           m->ScrollByWhole(sb, direction, ScrollSnapFlags::IntendedEndPosition);
 158         }
 159         break;
 160       case 3:
 161       default:
 162         // We were told to ignore this click, or someone assigned a non-standard
 163         // value to the button's action.
 164         return false;
 165     }
 166     if (!weakFrame.IsAlive()) {
 167       return false;
 168     }
 169
 170     if (!m) {
 171       sb->MoveToNewPosition(nsScrollbarFrame::ImplementsScrollByUnit::No);
 172       if (!weakFrame.IsAlive()) {
 173         return false;
 174       }
 175     }
 176   }
 177   if (repeat) {
 178     StartRepeat();
 179   }
 180   return true;
 181 }
 182
 183 NS_IMETHODIMP
 184 nsScrollbarButtonFrame::HandleRelease(nsPresContext* aPresContext,
 185                                       WidgetGUIEvent* aEvent,
 186                                       nsEventStatus* aEventStatus) {
 187   PresShell::ReleaseCapturingContent();
 188   // we're not active anymore
 189   mContent->AsElement()->UnsetAttr(kNameSpaceID_None, nsGkAtoms::active, true);
 190   StopRepeat();
 191   nsIFrame* scrollbar;
 192   GetParentWithTag(nsGkAtoms::scrollbar, this, scrollbar);
 193   nsScrollbarFrame* sb = do_QueryFrame(scrollbar);
 194   if (sb) {
 195     nsIScrollbarMediator* m = sb->GetScrollbarMediator();
 196     if (m) {
 197       m->ScrollbarReleased(sb);
 198     }
 199   }
 200   return NS_OK;
 201 }
 202
 203 void nsScrollbarButtonFrame::Notify() {
 204   if (mCursorOnThis ||
 205       LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarButtonAutoRepeatBehavior,
 206                           0)) {
 207     // get the scrollbar control
 208     nsIFrame* scrollbar;
 209     GetParentWithTag(nsGkAtoms::scrollbar, this, scrollbar);
 210     nsScrollbarFrame* sb = do_QueryFrame(scrollbar);
 211     if (sb) {
 212       nsIScrollbarMediator* m = sb->GetScrollbarMediator();
 213       if (m) {
 214         m->RepeatButtonScroll(sb);
 215       } else {
 216         sb->MoveToNewPosition(nsScrollbarFrame::ImplementsScrollByUnit::No);
 217       }
 218     }
 219   }
 220 }
 221
 222 nsresult nsScrollbarButtonFrame::GetChildWithTag(nsAtom* atom, nsIFrame* start,
 223                                                  nsIFrame*& result) {
 224   // recursively search our children
 225   for (nsIFrame* childFrame : start->PrincipalChildList()) {
 226     // get the content node
 227     nsIContent* child = childFrame->GetContent();
 228
 229     if (child) {
 230       // see if it is the child
 231       if (child->IsXULElement(atom)) {
 232         result = childFrame;
 233
 234         return NS_OK;
 235       }
 236     }
 237
 238     // recursive search the child
 239     GetChildWithTag(atom, childFrame, result);
 240     if (result != nullptr) return NS_OK;
 241   }
 242
 243   result = nullptr;
 244   return NS_OK;
 245 }
 246
 247 nsresult nsScrollbarButtonFrame::GetParentWithTag(nsAtom* toFind,
 248                                                   nsIFrame* start,
 249                                                   nsIFrame*& result) {
 250   while (start) {
 251     start = start->GetParent();
 252
 253     if (start) {
 254       // get the content node
 255       nsIContent* child = start->GetContent();
 256
 257       if (child && child->IsXULElement(toFind)) {
 258         result = start;
 259         return NS_OK;
 260       }
 261     }
 262   }
 263
 264   result = nullptr;
 265   return NS_OK;
 266 }
 267
 268 void nsScrollbarButtonFrame::DestroyFrom(nsIFrame* aDestructRoot,
 269                                          PostDestroyData& aPostDestroyData) {
 270   // Ensure our repeat service isn't going... it's possible that a scrollbar can
 271   // disappear out from under you while you're in the process of scrolling.
 272   StopRepeat();
 273   nsBoxFrame::DestroyFrom(aDestructRoot, aPostDestroyData);
 274 }