layout/forms/nsListControlFrame.h

   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 #ifndef nsListControlFrame_h___
   7 #define nsListControlFrame_h___
   8
   9 #ifdef DEBUG_evaughan
  10 // #define DEBUG_rods
  11 #endif
  12
  13 #ifdef DEBUG_rods
  14 // #define DO_REFLOW_DEBUG
  15 // #define DO_REFLOW_COUNTER
  16 // #define DO_UNCONSTRAINED_CHECK
  17 // #define DO_PIXELS
  18 #endif
  19
  20 #include "mozilla/Attributes.h"
  21 #include "mozilla/StaticPtr.h"
  22 #include "nsGfxScrollFrame.h"
  23 #include "nsIFormControlFrame.h"
  24 #include "nsISelectControlFrame.h"
  25 #include "nsSelectsAreaFrame.h"
  26
  27 class nsComboboxControlFrame;
  28 class nsPresContext;
  29
  30 namespace mozilla {
  31 class PresShell;
  32 class HTMLSelectEventListener;
  33
  34 namespace dom {
  35 class Event;
  36 class HTMLOptionElement;
  37 class HTMLSelectElement;
  38 class HTMLOptionsCollection;
  39 }  // namespace dom
  40 }  // namespace mozilla
  41
  42 /**
  43  * Frame-based listbox.
  44  */
  45
  46 class nsListControlFrame final : public nsHTMLScrollFrame,
  47                                  public nsIFormControlFrame,
  48                                  public nsISelectControlFrame {
  49  public:
  50   typedef mozilla::dom::HTMLOptionElement HTMLOptionElement;
  51
  52   friend nsListControlFrame* NS_NewListControlFrame(
  53       mozilla::PresShell* aPresShell, ComputedStyle* aStyle);
  54
  55   NS_DECL_QUERYFRAME
  56   NS_DECL_FRAMEARENA_HELPERS(nsListControlFrame)
  57
  58   Maybe<nscoord> GetNaturalBaselineBOffset(
  59       mozilla::WritingMode aWM, BaselineSharingGroup aBaselineGroup,
  60       BaselineExportContext) const override;
  61
  62   // nsIFrame
  63   nsresult HandleEvent(nsPresContext* aPresContext,
  64                        mozilla::WidgetGUIEvent* aEvent,
  65                        nsEventStatus* aEventStatus) final;
  66
  67   void SetInitialChildList(ChildListID aListID, nsFrameList&& aChildList) final;
  68
  69   nscoord GetPrefISize(gfxContext* aRenderingContext) final;
  70   nscoord GetMinISize(gfxContext* aRenderingContext) final;
  71
  72   void Reflow(nsPresContext* aCX, ReflowOutput& aDesiredSize,
  73               const ReflowInput& aReflowInput, nsReflowStatus& aStatus) final;
  74
  75   void Init(nsIContent* aContent, nsContainerFrame* aParent,
  76             nsIFrame* aPrevInFlow) final;
  77
  78   void DidReflow(nsPresContext* aPresContext,
  79                  const ReflowInput* aReflowInput) final;
  80   void Destroy(DestroyContext&) override;
  81
  82   void BuildDisplayList(nsDisplayListBuilder* aBuilder,
  83                         const nsDisplayListSet& aLists) final;
  84
  85   nsContainerFrame* GetContentInsertionFrame() final;
  86
  87   int32_t GetEndSelectionIndex() const { return mEndSelectionIndex; }
  88
  89   mozilla::dom::HTMLOptionElement* GetCurrentOption() const;
  90
  91 #ifdef DEBUG_FRAME_DUMP
  92   nsresult GetFrameName(nsAString& aResult) const final;
  93 #endif
  94
  95   // nsIFormControlFrame
  96   nsresult SetFormProperty(nsAtom* aName, const nsAString& aValue) final;
  97   MOZ_CAN_RUN_SCRIPT_BOUNDARY
  98   void SetFocus(bool aOn = true, bool aRepaint = false) final;
  99
 100   bool ShouldPropagateComputedBSizeToScrolledContent() const final;
 101
 102   // for accessibility purposes
 103 #ifdef ACCESSIBILITY
 104   mozilla::a11y::AccType AccessibleType() final;
 105 #endif
 106
 107   int32_t GetSelectedIndex();
 108
 109   /**
 110    * Gets the text of the currently selected item.
 111    * If the there are zero items then an empty string is returned
 112    * If there is nothing selected, then the 0th item's text is returned.
 113    */
 114   void GetOptionText(uint32_t aIndex, nsAString& aStr);
 115
 116   void CaptureMouseEvents(bool aGrabMouseEvents);
 117   nscoord GetBSizeOfARow();
 118   uint32_t GetNumberOfOptions();
 119
 120   MOZ_CAN_RUN_SCRIPT_BOUNDARY void OnContentReset();
 121
 122   // nsISelectControlFrame
 123   NS_IMETHOD AddOption(int32_t index) final;
 124   NS_IMETHOD RemoveOption(int32_t index) final;
 125   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 126   NS_IMETHOD DoneAddingChildren(bool aIsDone) final;
 127
 128   /**
 129    * Gets the content (an option) by index and then set it as
 130    * being selected or not selected.
 131    */
 132   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 133   NS_IMETHOD OnOptionSelected(int32_t aIndex, bool aSelected) final;
 134   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 135   NS_IMETHOD_(void)
 136   OnSetSelectedIndex(int32_t aOldIndex, int32_t aNewIndex) final;
 137
 138   /**
 139    * Mouse event listeners.
 140    * @note These methods might destroy the frame, pres shell and other objects.
 141    */
 142   MOZ_CAN_RUN_SCRIPT
 143   nsresult HandleLeftButtonMouseDown(mozilla::dom::Event* aMouseEvent);
 144   MOZ_CAN_RUN_SCRIPT
 145   nsresult HandleLeftButtonMouseUp(mozilla::dom::Event* aMouseEvent);
 146   MOZ_CAN_RUN_SCRIPT
 147   nsresult DragMove(mozilla::dom::Event* aMouseEvent);
 148   MOZ_CAN_RUN_SCRIPT
 149
 150   MOZ_CAN_RUN_SCRIPT
 151   bool PerformSelection(int32_t aClickedIndex, bool aIsShift, bool aIsControl);
 152   MOZ_CAN_RUN_SCRIPT
 153   void UpdateSelectionAfterKeyEvent(int32_t aNewIndex, uint32_t aCharCode,
 154                                     bool aIsShift, bool aIsControlOrMeta,
 155                                     bool aIsControlSelectMode);
 156
 157   /**
 158    * Returns the options collection for mContent, if any.
 159    */
 160   mozilla::dom::HTMLOptionsCollection* GetOptions() const;
 161   /**
 162    * Returns the HTMLOptionElement for a given index in mContent's collection.
 163    */
 164   HTMLOptionElement* GetOption(uint32_t aIndex) const;
 165
 166   // Helper
 167   bool IsFocused() { return this == mFocused; }
 168
 169   /**
 170    * Function to paint the focus rect when our nsSelectsAreaFrame is painting.
 171    * @param aPt the offset of this frame, relative to the rendering reference
 172    * frame
 173    */
 174   void PaintFocus(mozilla::gfx::DrawTarget* aDrawTarget, nsPoint aPt);
 175
 176   /**
 177    * If this frame IsFocused(), invalidates an area that includes anything
 178    * that PaintFocus will or could have painted --- basically the whole
 179    * GetOptionsContainer, plus some extra stuff if there are no options. This
 180    * must be called every time mEndSelectionIndex changes.
 181    */
 182   void InvalidateFocus();
 183
 184   /**
 185    * Function to calculate the block size of a row, for use with the
 186    * "size" attribute.
 187    * Can't be const because GetNumberOfOptions() isn't const.
 188    */
 189   nscoord CalcBSizeOfARow();
 190
 191   /**
 192    * Function to ask whether we're currently in what might be the
 193    * first pass of a two-pass reflow.
 194    */
 195   bool MightNeedSecondPass() const { return mMightNeedSecondPass; }
 196
 197   void SetSuppressScrollbarUpdate(bool aSuppress) {
 198     nsHTMLScrollFrame::SetSuppressScrollbarUpdate(aSuppress);
 199   }
 200
 201   /**
 202    * Return the number of displayed rows in the list.
 203    */
 204   uint32_t GetNumDisplayRows() const { return mNumDisplayRows; }
 205
 206 #ifdef ACCESSIBILITY
 207   /**
 208    * Post a custom DOM event for the change, so that accessibility can
 209    * fire a native focus event for accessibility
 210    * (Some 3rd party products need to track our focus)
 211    */
 212   void FireMenuItemActiveEvent(
 213       nsIContent* aPreviousOption);  // Inform assistive tech what got focused
 214 #endif
 215
 216  protected:
 217   /**
 218    * Updates the selected text in a combobox and then calls FireOnChange().
 219    * @note This method might destroy the frame, pres shell and other objects.
 220    * Returns false if calling it destroyed |this|.
 221    */
 222   MOZ_CAN_RUN_SCRIPT
 223   bool UpdateSelection();
 224
 225   /**
 226    * Returns whether mContent supports multiple selection.
 227    */
 228   bool GetMultiple() const {
 229     return mContent->AsElement()->HasAttr(nsGkAtoms::multiple);
 230   }
 231
 232   mozilla::dom::HTMLSelectElement& Select() const;
 233
 234   /**
 235    * @return true if the <option> at aIndex is selectable by the user.
 236    */
 237   bool IsOptionInteractivelySelectable(int32_t aIndex) const;
 238   /**
 239    * @return true if aOption in aSelect is selectable by the user.
 240    */
 241   static bool IsOptionInteractivelySelectable(
 242       mozilla::dom::HTMLSelectElement* aSelect,
 243       mozilla::dom::HTMLOptionElement* aOption);
 244
 245   MOZ_CAN_RUN_SCRIPT void ScrollToFrame(HTMLOptionElement& aOptElement);
 246
 247   MOZ_CAN_RUN_SCRIPT void ScrollToIndex(int32_t anIndex);
 248
 249  public:
 250   /**
 251    * Resets the select back to it's original default values;
 252    * those values as determined by the original HTML
 253    */
 254   MOZ_CAN_RUN_SCRIPT void ResetList(bool aAllowScrolling);
 255
 256  protected:
 257   explicit nsListControlFrame(ComputedStyle* aStyle,
 258                               nsPresContext* aPresContext);
 259   virtual ~nsListControlFrame();
 260
 261   /**
 262    * Sets the mSelectedIndex and mOldSelectedIndex from figuring out what
 263    * item was selected using content
 264    * @param aPoint the event point, in listcontrolframe coordinates
 265    * @return NS_OK if it successfully found the selection
 266    */
 267   nsresult GetIndexFromDOMEvent(mozilla::dom::Event* aMouseEvent,
 268                                 int32_t& aCurIndex);
 269
 270   bool CheckIfAllFramesHere();
 271
 272   // guess at a row block size based on our own style.
 273   nscoord CalcFallbackRowBSize(float aFontSizeInflation);
 274
 275   // CalcIntrinsicBSize computes our intrinsic block size (taking the
 276   // "size" attribute into account).  This should only be called in
 277   // non-dropdown mode.
 278   nscoord CalcIntrinsicBSize(nscoord aBSizeOfARow, int32_t aNumberOfOptions);
 279
 280   // Dropped down stuff
 281   void SetComboboxItem(int32_t aIndex);
 282
 283   // Selection
 284   bool SetOptionsSelectedFromFrame(int32_t aStartIndex, int32_t aEndIndex,
 285                                    bool aValue, bool aClearAll);
 286   bool ToggleOptionSelectedFromFrame(int32_t aIndex);
 287
 288   MOZ_CAN_RUN_SCRIPT
 289   bool SingleSelection(int32_t aClickedIndex, bool aDoToggle);
 290   bool ExtendedSelection(int32_t aStartIndex, int32_t aEndIndex,
 291                          bool aClearAll);
 292   MOZ_CAN_RUN_SCRIPT
 293   bool HandleListSelection(mozilla::dom::Event* aDOMEvent,
 294                            int32_t selectedIndex);
 295   void InitSelectionRange(int32_t aClickedIndex);
 296
 297  public:
 298   nsSelectsAreaFrame* GetOptionsContainer() const {
 299     return static_cast<nsSelectsAreaFrame*>(GetScrolledFrame());
 300   }
 301
 302   static constexpr int32_t kNothingSelected = -1;
 303
 304  protected:
 305   nscoord BSizeOfARow() { return GetOptionsContainer()->BSizeOfARow(); }
 306
 307   /**
 308    * @return how many displayable options/optgroups this frame has.
 309    */
 310   uint32_t GetNumberOfRows();
 311
 312   // Data Members
 313   int32_t mStartSelectionIndex;
 314   int32_t mEndSelectionIndex;
 315
 316   uint32_t mNumDisplayRows;
 317   bool mChangesSinceDragStart : 1;
 318
 319   // Has the user selected a visible item since we showed the dropdown?
 320   bool mItemSelectionStarted : 1;
 321
 322   bool mIsAllContentHere : 1;
 323   bool mIsAllFramesHere : 1;
 324   bool mHasBeenInitialized : 1;
 325   bool mNeedToReset : 1;
 326   bool mPostChildrenLoadedReset : 1;
 327
 328   // True if we're in the middle of a reflow and might need a second
 329   // pass.  This only happens for auto heights.
 330   bool mMightNeedSecondPass : 1;
 331
 332   /**
 333    * Set to aPresContext->HasPendingInterrupt() at the start of Reflow.
 334    * Set to false at the end of DidReflow.
 335    */
 336   bool mHasPendingInterruptAtStartOfReflow : 1;
 337
 338   // True if the selection can be set to nothing or disabled options.
 339   bool mForceSelection : 1;
 340
 341   RefPtr<mozilla::HTMLSelectEventListener> mEventListener;
 342
 343   static nsListControlFrame* mFocused;
 344
 345 #ifdef DO_REFLOW_COUNTER
 346   int32_t mReflowId;
 347 #endif
 348 };
 349
 350 #endif /* nsListControlFrame_h___ */