layout/forms/nsIComboboxControlFrame.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsIComboboxControlFrame_h___
   7 #define nsIComboboxControlFrame_h___
   8
   9 #include "nsQueryFrame.h"
  10
  11 /**
  12   * nsIComboboxControlFrame is the interface for comboboxes.
  13   */
  14 class nsIComboboxControlFrame : public nsQueryFrame
  15 {
  16 public:
  17   NS_DECL_QUERYFRAME_TARGET(nsIComboboxControlFrame)
  18
  19   /**
  20    * Indicates whether the list is dropped down
  21    */
  22   virtual bool IsDroppedDown() = 0;
  23
  24   /**
  25    * Shows or hides the drop down
  26    */
  27   virtual void ShowDropDown(bool aDoDropDown) = 0;
  28
  29   /**
  30    * Gets the Drop Down List
  31    */
  32   virtual nsIFrame* GetDropDown() = 0;
  33
  34   /**
  35    * Sets the Drop Down List
  36    */
  37   virtual void SetDropDown(nsIFrame* aDropDownFrame) = 0;
  38
  39   /**
  40    * Tells the combobox to roll up
  41    */
  42   virtual void RollupFromList() = 0;
  43
  44   /**
  45    * Redisplay the selected text (will do nothing if text has not changed).
  46    * This method might destroy this frame or any others that happen to be
  47    * around.  It might even run script.
  48    */
  49   NS_IMETHOD RedisplaySelectedText() = 0;
  50
  51   /**
  52    * Method for the listbox to set and get the recent index
  53    */
  54   virtual int32_t UpdateRecentIndex(int32_t aIndex) = 0;
  55
  56   /**
  57    * Notification that the content has been reset
  58    */
  59   virtual void OnContentReset() = 0;
  60
  61   /**
  62    * This returns the index of the item that is currently being displayed
  63    * in the display area. It may differ from what the currently Selected index
  64    * is in in the dropdown.
  65    *
  66    * Detailed explanation:
  67    * When the dropdown is dropped down via a mouse click and the user moves the mouse
  68    * up and down without clicking, the currently selected item is being tracking inside
  69    * the dropdown, but the combobox is not being updated. When the user selects items
  70    * with the arrow keys, the combobox is being updated. So when the user clicks outside
  71    * the dropdown and it needs to roll up it has to decide whether to keep the current
  72    * selection or not. This method is used to get the current index in the combobox to
  73    * compare it to the current index in the dropdown to see if the combox has been updated
  74    * and that way it knows whether to "cancel" the current selection residing in the
  75    * dropdown. Or whether to leave the selection alone.
  76    */
  77   virtual int32_t GetIndexOfDisplayArea() = 0;
  78 };
  79
  80 #endif
  81