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 NS_IMPL_FRAMEARENA_HELPERS(nsScrollbarButtonFrame)
  43
  44 nsresult nsScrollbarButtonFrame::HandleEvent(nsPresContext* aPresContext,
  45                                              WidgetGUIEvent* aEvent,
  46                                              nsEventStatus* aEventStatus) {
  47   NS_ENSURE_ARG_POINTER(aEventStatus);
  48
  49   // If a web page calls event.preventDefault() we still want to
  50   // scroll when scroll arrow is clicked. See bug 511075.
  51   if (!mContent->IsInNativeAnonymousSubtree() &&
  52       nsEventStatus_eConsumeNoDefault == *aEventStatus) {
  53     return NS_OK;
  54   }
  55
  56   switch (aEvent->mMessage) {
  57     case eMouseDown:
  58       mCursorOnThis = true;
  59       // if we didn't handle the press ourselves, pass it on to the superclass
  60       if (HandleButtonPress(aPresContext, aEvent, aEventStatus)) {
  61         return NS_OK;
  62       }
  63       break;
  64     case eMouseUp:
  65       HandleRelease(aPresContext, aEvent, aEventStatus);
  66       break;
  67     case eMouseOut:
  68       mCursorOnThis = false;
  69       break;
  70     case eMouseMove: {
  71       nsPoint cursor = nsLayoutUtils::GetEventCoordinatesRelativeTo(
  72           aEvent, RelativeTo{this});
  73       nsRect frameRect(nsPoint(0, 0), GetSize());
  74       mCursorOnThis = frameRect.Contains(cursor);
  75       break;
  76     }
  77     default:
  78       break;
  79   }
  80
  81   return SimpleXULLeafFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
  82 }
  83
  84 bool nsScrollbarButtonFrame::HandleButtonPress(nsPresContext* aPresContext,
  85                                                WidgetGUIEvent* aEvent,
  86                                                nsEventStatus* aEventStatus) {
  87   // Get the desired action for the scrollbar button.
  88   LookAndFeel::IntID tmpAction;
  89   uint16_t button = aEvent->AsMouseEvent()->mButton;
  90   if (button == MouseButton::ePrimary) {
  91     tmpAction = LookAndFeel::IntID::ScrollButtonLeftMouseButtonAction;
  92   } else if (button == MouseButton::eMiddle) {
  93     tmpAction = LookAndFeel::IntID::ScrollButtonMiddleMouseButtonAction;
  94   } else if (button == MouseButton::eSecondary) {
  95     tmpAction = LookAndFeel::IntID::ScrollButtonRightMouseButtonAction;
  96   } else {
  97     return false;
  98   }
  99
 100   // Get the button action metric from the pres. shell.
 101   int32_t pressedButtonAction;
 102   if (NS_FAILED(LookAndFeel::GetInt(tmpAction, &pressedButtonAction))) {
 103     return false;
 104   }
 105
 106   // get the scrollbar control
 107   nsIFrame* scrollbar;
 108   GetParentWithTag(nsGkAtoms::scrollbar, this, scrollbar);
 109
 110   if (scrollbar == nullptr) return false;
 111
 112   static dom::Element::AttrValuesArray strings[] = {
 113       nsGkAtoms::increment, nsGkAtoms::decrement, nullptr};
 114   int32_t index = mContent->AsElement()->FindAttrValueIn(
 115       kNameSpaceID_None, nsGkAtoms::type, strings, eCaseMatters);
 116   int32_t direction;
 117   if (index == 0)
 118     direction = 1;
 119   else if (index == 1)
 120     direction = -1;
 121   else
 122     return false;
 123
 124   bool repeat = pressedButtonAction != 2;
 125
 126   PresShell::SetCapturingContent(mContent, CaptureFlags::IgnoreAllowedState);
 127
 128   AutoWeakFrame weakFrame(this);
 129
 130   if (nsScrollbarFrame* sb = do_QueryFrame(scrollbar)) {
 131     nsIScrollbarMediator* m = sb->GetScrollbarMediator();
 132     switch (pressedButtonAction) {
 133       case 0:
 134         sb->SetIncrementToLine(direction);
 135         if (m) {
 136           m->ScrollByLine(sb, direction, ScrollSnapFlags::IntendedDirection);
 137         }
 138         break;
 139       case 1:
 140         sb->SetIncrementToPage(direction);
 141         if (m) {
 142           m->ScrollByPage(sb, direction,
 143                           ScrollSnapFlags::IntendedDirection |
 144                               ScrollSnapFlags::IntendedEndPosition);
 145         }
 146         break;
 147       case 2:
 148         sb->SetIncrementToWhole(direction);
 149         if (m) {
 150           m->ScrollByWhole(sb, direction, ScrollSnapFlags::IntendedEndPosition);
 151         }
 152         break;
 153       case 3:
 154       default:
 155         // We were told to ignore this click, or someone assigned a non-standard
 156         // value to the button's action.
 157         return false;
 158     }
 159     if (!weakFrame.IsAlive()) {
 160       return false;
 161     }
 162
 163     if (!m) {
 164       sb->MoveToNewPosition(nsScrollbarFrame::ImplementsScrollByUnit::No);
 165       if (!weakFrame.IsAlive()) {
 166         return false;
 167       }
 168     }
 169   }
 170   if (repeat) {
 171     StartRepeat();
 172   }
 173   return true;
 174 }
 175
 176 NS_IMETHODIMP
 177 nsScrollbarButtonFrame::HandleRelease(nsPresContext* aPresContext,
 178                                       WidgetGUIEvent* aEvent,
 179                                       nsEventStatus* aEventStatus) {
 180   PresShell::ReleaseCapturingContent();
 181   StopRepeat();
 182   nsIFrame* scrollbar;
 183   GetParentWithTag(nsGkAtoms::scrollbar, this, scrollbar);
 184   nsScrollbarFrame* sb = do_QueryFrame(scrollbar);
 185   if (sb) {
 186     nsIScrollbarMediator* m = sb->GetScrollbarMediator();
 187     if (m) {
 188       m->ScrollbarReleased(sb);
 189     }
 190   }
 191   return NS_OK;
 192 }
 193
 194 void nsScrollbarButtonFrame::Notify() {
 195   if (mCursorOnThis ||
 196       LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarButtonAutoRepeatBehavior,
 197                           0)) {
 198     // get the scrollbar control
 199     nsIFrame* scrollbar;
 200     GetParentWithTag(nsGkAtoms::scrollbar, this, scrollbar);
 201     nsScrollbarFrame* sb = do_QueryFrame(scrollbar);
 202     if (sb) {
 203       nsIScrollbarMediator* m = sb->GetScrollbarMediator();
 204       if (m) {
 205         m->RepeatButtonScroll(sb);
 206       } else {
 207         sb->MoveToNewPosition(nsScrollbarFrame::ImplementsScrollByUnit::No);
 208       }
 209     }
 210   }
 211 }
 212
 213 nsresult nsScrollbarButtonFrame::GetChildWithTag(nsAtom* atom, nsIFrame* start,
 214                                                  nsIFrame*& result) {
 215   // recursively search our children
 216   for (nsIFrame* childFrame : start->PrincipalChildList()) {
 217     // get the content node
 218     nsIContent* child = childFrame->GetContent();
 219
 220     if (child) {
 221       // see if it is the child
 222       if (child->IsXULElement(atom)) {
 223         result = childFrame;
 224
 225         return NS_OK;
 226       }
 227     }
 228
 229     // recursive search the child
 230     GetChildWithTag(atom, childFrame, result);
 231     if (result != nullptr) return NS_OK;
 232   }
 233
 234   result = nullptr;
 235   return NS_OK;
 236 }
 237
 238 nsresult nsScrollbarButtonFrame::GetParentWithTag(nsAtom* toFind,
 239                                                   nsIFrame* start,
 240                                                   nsIFrame*& result) {
 241   while (start) {
 242     start = start->GetParent();
 243
 244     if (start) {
 245       // get the content node
 246       nsIContent* child = start->GetContent();
 247
 248       if (child && child->IsXULElement(toFind)) {
 249         result = start;
 250         return NS_OK;
 251       }
 252     }
 253   }
 254
 255   result = nullptr;
 256   return NS_OK;
 257 }
 258
 259 void nsScrollbarButtonFrame::Destroy(DestroyContext& aContext) {
 260   // Ensure our repeat service isn't going... it's possible that a scrollbar can
 261   // disappear out from under you while you're in the process of scrolling.
 262   StopRepeat();
 263   SimpleXULLeafFrame::Destroy(aContext);
 264 }