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   // nsIFrame
  59   nsresult HandleEvent(nsPresContext* aPresContext,
  60                        mozilla::WidgetGUIEvent* aEvent,
  61                        nsEventStatus* aEventStatus) final;
  62
  63   void SetInitialChildList(ChildListID aListID, nsFrameList& aChildList) final;
  64
  65   nscoord GetPrefISize(gfxContext* aRenderingContext) final;
  66   nscoord GetMinISize(gfxContext* aRenderingContext) final;
  67
  68   void Reflow(nsPresContext* aCX, ReflowOutput& aDesiredSize,
  69               const ReflowInput& aReflowInput, nsReflowStatus& aStatus) final;
  70
  71   void Init(nsIContent* aContent, nsContainerFrame* aParent,
  72             nsIFrame* aPrevInFlow) final;
  73
  74   MOZ_CAN_RUN_SCRIPT_BOUNDARY
  75   void DidReflow(nsPresContext* aPresContext,
  76                  const ReflowInput* aReflowInput) final;
  77   void DestroyFrom(nsIFrame* aDestructRoot,
  78                    PostDestroyData& aPostDestroyData) final;
  79
  80   void BuildDisplayList(nsDisplayListBuilder* aBuilder,
  81                         const nsDisplayListSet& aLists) final;
  82
  83   nsContainerFrame* GetContentInsertionFrame() final;
  84
  85   int32_t GetEndSelectionIndex() const { return mEndSelectionIndex; }
  86
  87   mozilla::dom::HTMLOptionElement* GetCurrentOption() const;
  88
  89   bool IsFrameOfType(uint32_t aFlags) const final {
  90     return nsHTMLScrollFrame::IsFrameOfType(
  91         aFlags & ~(nsIFrame::eReplaced | nsIFrame::eReplacedContainsBlock));
  92   }
  93
  94 #ifdef DEBUG_FRAME_DUMP
  95   nsresult GetFrameName(nsAString& aResult) const final;
  96 #endif
  97
  98   // nsIFormControlFrame
  99   nsresult SetFormProperty(nsAtom* aName, const nsAString& aValue) final;
 100   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 101   void SetFocus(bool aOn = true, bool aRepaint = false) final;
 102
 103   mozilla::ScrollStyles GetScrollStyles() const final;
 104   bool ShouldPropagateComputedBSizeToScrolledContent() const final;
 105
 106   // for accessibility purposes
 107 #ifdef ACCESSIBILITY
 108   mozilla::a11y::AccType AccessibleType() final;
 109 #endif
 110
 111   int32_t GetSelectedIndex();
 112
 113   /**
 114    * Gets the text of the currently selected item.
 115    * If the there are zero items then an empty string is returned
 116    * If there is nothing selected, then the 0th item's text is returned.
 117    */
 118   void GetOptionText(uint32_t aIndex, nsAString& aStr);
 119
 120   void CaptureMouseEvents(bool aGrabMouseEvents);
 121   nscoord GetBSizeOfARow();
 122   uint32_t GetNumberOfOptions();
 123
 124   MOZ_CAN_RUN_SCRIPT_BOUNDARY void OnContentReset();
 125
 126   // nsISelectControlFrame
 127   NS_IMETHOD AddOption(int32_t index) final;
 128   NS_IMETHOD RemoveOption(int32_t index) final;
 129   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 130   NS_IMETHOD DoneAddingChildren(bool aIsDone) final;
 131
 132   /**
 133    * Gets the content (an option) by index and then set it as
 134    * being selected or not selected.
 135    */
 136   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 137   NS_IMETHOD OnOptionSelected(int32_t aIndex, bool aSelected) final;
 138   MOZ_CAN_RUN_SCRIPT_BOUNDARY
 139   NS_IMETHOD_(void)
 140   OnSetSelectedIndex(int32_t aOldIndex, int32_t aNewIndex) final;
 141
 142   /**
 143    * Mouse event listeners.
 144    * @note These methods might destroy the frame, pres shell and other objects.
 145    */
 146   MOZ_CAN_RUN_SCRIPT
 147   nsresult HandleLeftButtonMouseDown(mozilla::dom::Event* aMouseEvent);
 148   MOZ_CAN_RUN_SCRIPT
 149   nsresult HandleLeftButtonMouseUp(mozilla::dom::Event* aMouseEvent);
 150   MOZ_CAN_RUN_SCRIPT
 151   nsresult DragMove(mozilla::dom::Event* aMouseEvent);
 152   MOZ_CAN_RUN_SCRIPT
 153
 154   MOZ_CAN_RUN_SCRIPT
 155   bool PerformSelection(int32_t aClickedIndex, bool aIsShift, bool aIsControl);
 156   MOZ_CAN_RUN_SCRIPT
 157   void UpdateSelectionAfterKeyEvent(int32_t aNewIndex, uint32_t aCharCode,
 158                                     bool aIsShift, bool aIsControlOrMeta,
 159                                     bool aIsControlSelectMode);
 160
 161   /**
 162    * Returns the options collection for mContent, if any.
 163    */
 164   mozilla::dom::HTMLOptionsCollection* GetOptions() const;
 165   /**
 166    * Returns the HTMLOptionElement for a given index in mContent's collection.
 167    */
 168   HTMLOptionElement* GetOption(uint32_t aIndex) const;
 169
 170   // Helper
 171   bool IsFocused() { return this == mFocused; }
 172
 173   /**
 174    * Function to paint the focus rect when our nsSelectsAreaFrame is painting.
 175    * @param aPt the offset of this frame, relative to the rendering reference
 176    * frame
 177    */
 178   void PaintFocus(mozilla::gfx::DrawTarget* aDrawTarget, nsPoint aPt);
 179
 180   /**
 181    * If this frame IsFocused(), invalidates an area that includes anything
 182    * that PaintFocus will or could have painted --- basically the whole
 183    * GetOptionsContainer, plus some extra stuff if there are no options. This
 184    * must be called every time mEndSelectionIndex changes.
 185    */
 186   void InvalidateFocus();
 187
 188   /**
 189    * Function to calculate the block size of a row, for use with the
 190    * "size" attribute.
 191    * Can't be const because GetNumberOfOptions() isn't const.
 192    */
 193   nscoord CalcBSizeOfARow();
 194
 195   /**
 196    * Function to ask whether we're currently in what might be the
 197    * first pass of a two-pass reflow.
 198    */
 199   bool MightNeedSecondPass() const { return mMightNeedSecondPass; }
 200
 201   void SetSuppressScrollbarUpdate(bool aSuppress) {
 202     nsHTMLScrollFrame::SetSuppressScrollbarUpdate(aSuppress);
 203   }
 204
 205   /**
 206    * Return the number of displayed rows in the list.
 207    */
 208   uint32_t GetNumDisplayRows() const { return mNumDisplayRows; }
 209
 210 #ifdef ACCESSIBILITY
 211   /**
 212    * Post a custom DOM event for the change, so that accessibility can
 213    * fire a native focus event for accessibility
 214    * (Some 3rd party products need to track our focus)
 215    */
 216   void FireMenuItemActiveEvent(
 217       nsIContent* aPreviousOption);  // Inform assistive tech what got focused
 218 #endif
 219
 220  protected:
 221   /**
 222    * Updates the selected text in a combobox and then calls FireOnChange().
 223    * @note This method might destroy the frame, pres shell and other objects.
 224    * Returns false if calling it destroyed |this|.
 225    */
 226   MOZ_CAN_RUN_SCRIPT
 227   bool UpdateSelection();
 228
 229   /**
 230    * Returns whether mContent supports multiple selection.
 231    */
 232   bool GetMultiple() const {
 233     return mContent->AsElement()->HasAttr(kNameSpaceID_None,
 234                                           nsGkAtoms::multiple);
 235   }
 236
 237   mozilla::dom::HTMLSelectElement& Select() const;
 238
 239   /**
 240    * @return true if the <option> at aIndex is selectable by the user.
 241    */
 242   bool IsOptionInteractivelySelectable(int32_t aIndex) const;
 243   /**
 244    * @return true if aOption in aSelect is selectable by the user.
 245    */
 246   static bool IsOptionInteractivelySelectable(
 247       mozilla::dom::HTMLSelectElement* aSelect,
 248       mozilla::dom::HTMLOptionElement* aOption);
 249
 250   MOZ_CAN_RUN_SCRIPT void ScrollToFrame(HTMLOptionElement& aOptElement);
 251
 252   MOZ_CAN_RUN_SCRIPT void ScrollToIndex(int32_t anIndex);
 253
 254   /**
 255    * Resets the select back to it's original default values;
 256    * those values as determined by the original HTML
 257    */
 258   MOZ_CAN_RUN_SCRIPT void ResetList(bool aAllowScrolling);
 259
 260   explicit nsListControlFrame(ComputedStyle* aStyle,
 261                               nsPresContext* aPresContext);
 262   virtual ~nsListControlFrame();
 263
 264   /**
 265    * Sets the mSelectedIndex and mOldSelectedIndex from figuring out what
 266    * item was selected using content
 267    * @param aPoint the event point, in listcontrolframe coordinates
 268    * @return NS_OK if it successfully found the selection
 269    */
 270   nsresult GetIndexFromDOMEvent(mozilla::dom::Event* aMouseEvent,
 271                                 int32_t& aCurIndex);
 272
 273   bool CheckIfAllFramesHere();
 274
 275   // guess at a row block size based on our own style.
 276   nscoord CalcFallbackRowBSize(float aFontSizeInflation);
 277
 278   // CalcIntrinsicBSize computes our intrinsic block size (taking the
 279   // "size" attribute into account).  This should only be called in
 280   // non-dropdown mode.
 281   nscoord CalcIntrinsicBSize(nscoord aBSizeOfARow, int32_t aNumberOfOptions);
 282
 283   // Dropped down stuff
 284   void SetComboboxItem(int32_t aIndex);
 285
 286   // Selection
 287   bool SetOptionsSelectedFromFrame(int32_t aStartIndex, int32_t aEndIndex,
 288                                    bool aValue, bool aClearAll);
 289   bool ToggleOptionSelectedFromFrame(int32_t aIndex);
 290
 291   MOZ_CAN_RUN_SCRIPT
 292   bool SingleSelection(int32_t aClickedIndex, bool aDoToggle);
 293   bool ExtendedSelection(int32_t aStartIndex, int32_t aEndIndex,
 294                          bool aClearAll);
 295   MOZ_CAN_RUN_SCRIPT
 296   bool HandleListSelection(mozilla::dom::Event* aDOMEvent,
 297                            int32_t selectedIndex);
 298   void InitSelectionRange(int32_t aClickedIndex);
 299
 300  public:
 301   nsSelectsAreaFrame* GetOptionsContainer() const {
 302     return static_cast<nsSelectsAreaFrame*>(GetScrolledFrame());
 303   }
 304
 305   static constexpr int32_t kNothingSelected = -1;
 306
 307  protected:
 308   nscoord BSizeOfARow() { return GetOptionsContainer()->BSizeOfARow(); }
 309
 310   /**
 311    * @return how many displayable options/optgroups this frame has.
 312    */
 313   uint32_t GetNumberOfRows();
 314
 315   // Data Members
 316   int32_t mStartSelectionIndex;
 317   int32_t mEndSelectionIndex;
 318
 319   uint32_t mNumDisplayRows;
 320   bool mChangesSinceDragStart : 1;
 321
 322   // Has the user selected a visible item since we showed the dropdown?
 323   bool mItemSelectionStarted : 1;
 324
 325   bool mIsAllContentHere : 1;
 326   bool mIsAllFramesHere : 1;
 327   bool mHasBeenInitialized : 1;
 328   bool mNeedToReset : 1;
 329   bool mPostChildrenLoadedReset : 1;
 330
 331   // True if we're in the middle of a reflow and might need a second
 332   // pass.  This only happens for auto heights.
 333   bool mMightNeedSecondPass : 1;
 334
 335   /**
 336    * Set to aPresContext->HasPendingInterrupt() at the start of Reflow.
 337    * Set to false at the end of DidReflow.
 338    */
 339   bool mHasPendingInterruptAtStartOfReflow : 1;
 340
 341   // True if the selection can be set to nothing or disabled options.
 342   bool mForceSelection : 1;
 343
 344   // The last computed block size we reflowed at if we're a combobox
 345   // dropdown.
 346   // XXXbz should we be using a subclass here?  Or just not worry
 347   // about the extra member on listboxes?
 348   nscoord mLastDropdownComputedBSize;
 349
 350   // At the time of our last dropdown, the backstop color to draw in case we
 351   // are translucent.
 352   nscolor mLastDropdownBackstopColor;
 353
 354   RefPtr<mozilla::HTMLSelectEventListener> mEventListener;
 355
 356   static nsListControlFrame* mFocused;
 357
 358 #ifdef DO_REFLOW_COUNTER
 359   int32_t mReflowId;
 360 #endif
 361 };
 362
 363 #endif /* nsListControlFrame_h___ */