interface/wx/headerctrl.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/headerctrl.h
   3 // Purpose:     interface of wxHeaderCtrl
   4 // Author:      Vadim Zeitlin
   5 // Created:     2008-12-01
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2008 Vadim Zeitlin <vadim@wxwidgets.org>
   8 // Licence:     wxWindows license
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 /**
  12     @class wxHeaderCtrl
  13
  14     wxHeaderCtrl is the control containing the column headings which is usually
  15     used for display of tabular data.
  16
  17     It is used as part of wxGrid and (will be used in the near future) in
  18     in wxDataViewCtrl and report view of wxListCtrl but can be also used
  19     independently. In general this class is meant to be used as part of another
  20     control which already stores the column information somewhere as it can't
  21     be used directly: instead you need to inherit from it and implement the
  22     GetColumn() method to provide column information. See wxHeaderCtrlSimple
  23     for a concrete control class which can be used directly.
  24
  25     In addition to labeling the columns, the control has the following
  26     features:
  27         - Column reordering support, either by explicitly configuring the
  28           columns order and calling SetColumnsOrder() or by dragging the
  29           columns interactively (if enabled).
  30         - Display of the icons in the header: this is often used to display a
  31           sort or reverse sort indicator when the column header is clicked.
  32
  33     Notice that this control itself doesn't do anything other than displaying
  34     the column headers. In particular column reordering and sorting must still
  35     be supported by the associated control displaying the real data under the
  36     header. Also remember to call ScrollWindow() method of the control if the
  37     associated data display window has a horizontal scrollbar, otherwise the
  38     headers wouldn't align with the data when the window is scrolled.
  39
  40     This control is implemented using the native header control under MSW
  41     systems and a generic implementation elsewhere.
  42
  43     @beginStyleTable
  44         @style{wxHD_DRAGDROP}
  45             If this style is specified (it is by default), the user can reorder
  46             the control columns by dragging them.
  47         @style{wxHD_DEFAULT_STYLE}
  48             Symbolic name for the default control style, currently equal to @c
  49             wxHD_DRAGDROP.
  50     @endStyleTable
  51
  52     @beginEventTable{wxHeaderCtrlEvent}
  53         @event{EVT_HEADER_CLICK(id, func)}
  54             A column heading was clicked.
  55         @event{EVT_HEADER_RIGHT_CLICK(id, func)}
  56             A column heading was right clicked.
  57         @event{EVT_HEADER_MIDDLE_CLICK(id, func)}
  58             A column heading was clicked with the middle mouse button.
  59
  60         @event{EVT_HEADER_DCLICK(id, func)}
  61             A column heading was double clicked.
  62         @event{EVT_HEADER_RIGHT_DCLICK(id, func)}
  63             A column heading was right double clicked.
  64         @event{EVT_HEADER_MIDDLE_DCLICK(id, func)}
  65             A column heading was double clicked with the middle mouse button.
  66
  67         @event{EVT_HEADER_SEPARATOR_DCLICK(id, func)}
  68             Separator to the right of the specified column was double clicked
  69             (this action is commonly used to resize the column to fit its
  70             contents width and the control provides UpdateColumnWidthToFit() method
  71             to make implementing this easier).
  72
  73         @event{EVT_HEADER_BEGIN_DRAG(id, func)}
  74             The user started to drag the column with the specified index (this
  75             can only happen if wxHeaderColumn::IsResizeable() returned true for
  76             this column). The event can be vetoed to prevent the control from
  77             being resized, if it isn't, the dragging and end drag events will
  78             be generated later.
  79         @event{EVT_HEADER_DRAGGING(id, func)}
  80             The user is dragging the column with the specified index and its
  81             current width is wxHeaderCtrlEvent::GetWidth(). The event can be
  82             vetoed to stop the dragging operation completely at any time.
  83         @event{EVT_HEADER_END_DRAG(id, func)}
  84             The user stopped dragging the column. If
  85             wxHeaderCtrlEvent::IsCancelled() returns @true, nothing should
  86             be done, otherwise the column should normally be resized to the
  87             value of wxHeaderCtrlEvent::GetWidth().
  88     @endEventTable
  89
  90     @library{wxcore}
  91     @category{ctrl}
  92
  93     @see wxGrid, wxListCtrl, wxDataViewCtrl
  94
  95
  96     @section headerctrl_improvements Future Improvements
  97
  98     Some features are supported by the native MSW control and so could be
  99     easily implemented in this version of wxHeaderCtrl but need to be
 100     implemented in the generic version as well to be really useful. Please let
 101     us know if you need or, better, plan to work on implementing, any of them:
 102         - Displaying bitmaps instead of or together with the text
 103         - Custom drawn headers
 104         - Filters associated with a column.
 105 */
 106 class wxHeaderCtrl
 107 {
 108 public:
 109     /**
 110         Default constructor not creating the underlying window.
 111
 112         You must use Create() after creating the object using this constructor.
 113      */
 114     wxHeaderCtrl();
 115
 116     /**
 117         Constructor creating the window.
 118
 119         Please see Create() for the parameters documentation.
 120      */
 121     wxHeaderCtrl(wxWindow *parent,
 122                  wxWindowID winid = wxID_ANY,
 123                  const wxPoint& pos = wxDefaultPosition,
 124                  const wxSize& size = wxDefaultSize,
 125                  long style = wxHD_DEFAULT_STYLE,
 126                  const wxString& name = wxHeaderCtrlNameStr);
 127
 128     /**
 129         Create the header control window.
 130
 131         @param parent
 132             The parent window. The header control should be typically
 133             positioned along the top edge of this window.
 134         @param winid
 135             Id of the control or @c wxID_ANY if you don't care.
 136         @param pos
 137             The initial position of the control.
 138         @param size
 139             The initial size of the control (usually not very useful as this
 140             control will typically be resized to have the same width as the
 141             associated data display control).
 142         @param style
 143             The control style, @c wxHD_DEFAULT_STYLE by default. Notice that
 144             the default style allows the user to reorder the columns by
 145             dragging them and you need to explicitly turn this feature off by
 146             using @code wxHD_DEFAULT_STYLE & ~wxHD_DRAGDROP @endcode if this is
 147             undesirable.
 148         @param name
 149             The name of the control.
 150      */
 151     bool Create(wxWindow *parent,
 152                 wxWindowID winid = wxID_ANY,
 153                 const wxPoint& pos = wxDefaultPosition,
 154                 const wxSize& size = wxDefaultSize,
 155                 long style = wxHD_DEFAULT_STYLE,
 156                 const wxString& name = wxHeaderCtrlNameStr);
 157
 158     /**
 159         Set the number of columns in the control.
 160
 161         The control will use GetColumn() to get information about all the
 162         new columns and refresh itself, i.e. this method also has the same
 163         effect as calling UpdateColumn() for all columns but it should only be
 164         used if the number of columns really changed.
 165      */
 166     void SetColumnCount(unsigned int count);
 167
 168     /**
 169         Return the number of columns in the control.
 170
 171         @return
 172             Number of columns as previously set by SetColumnCount().
 173
 174         @see IsEmpty()
 175      */
 176     unsigned int GetColumnCount() const;
 177
 178     /**
 179         Return whether the control has any columns.
 180
 181         @see GetColumnCount()
 182      */
 183     bool IsEmpty() const;
 184
 185 protected:
 186     /**
 187         Method to be implemented by the derived classes to return the
 188         information for the given column.
 189
 190         @param idx
 191             The column index, between 0 and the value last passed to
 192             SetColumnCount().
 193      */
 194     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 195
 196     /**
 197         Method which may be implemented by the derived classes to allow double
 198         clicking the column separator to resize the column to fit its contents.
 199
 200         When a separator is double clicked, the default handler of
 201         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 202         column if it returns @true so to implement the resizing of the column
 203         to fit its width on header double click you need to implement this
 204         method using logic similar to this example:
 205         @code
 206             class MyHeaderCtrl : public wxHeaderColumnBase
 207             {
 208             public:
 209                 ...
 210
 211                 void SetWidth(int width) { m_width = width; }
 212                 virtual int GetWidth() const { return m_width; }
 213
 214             private:
 215                 int m_width;
 216             };
 217
 218             class MyHeaderCtrl : public wxHeaderCtrl
 219             {
 220             public:
 221             protected:
 222                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 223                 {
 224                     return m_cols[idx];
 225                 }
 226
 227                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 228                 {
 229                     int widthContents = ... compute minimal width for column idx ...
 230                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 231                     return true;
 232                 }
 233
 234                 wxVector<MyHeaderColumn> m_cols;
 235             };
 236         @endcode
 237
 238         Base class version simply returns @false.
 239
 240         @param width
 241             Contains minimal width needed to display the column header itself
 242             and will usually be used as a starting point for the fitting width
 243             calculation.
 244         @return
 245             @true to indicate that the column was resized, i.e. GetColumn() now
 246             returns the new width value, and so must be refreshed or @false
 247             meaning that the control didn't reach to the separator double click.
 248      */
 249     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 250 };
 251
 252
 253 /**
 254     @class wxHeaderCtrlSimple
 255
 256     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 257     without inheriting from it as you need to do when using wxHeaderCtrl
 258     itself.
 259
 260     When using it, you need to use simple AppendColumn(), InsertColumn() and
 261     DeleteColumn() methods instead of setting the number of columns with
 262     SetColumnCount() and returning the information about them from the
 263     overridden GetColumn().
 264
 265     @library{wxcore}
 266     @category{ctrl}
 267
 268     @see wxHeaderCtrl
 269 */
 270 class wxHeaderCtrlSimple : public wxHeaderCtrl
 271 {
 272 public:
 273     /**
 274         Default constructor not creating the underlying window.
 275
 276         You must use Create() after creating the object using this constructor.
 277      */
 278     wxHeaderCtrlSimple();
 279
 280     /**
 281         Constructor creating the window.
 282
 283         Please see the base class wxHeaderCtrl::Create() method for the
 284         parameters description.
 285      */
 286     wxHeaderCtrlSimple(wxWindow *parent,
 287                        wxWindowID winid = wxID_ANY,
 288                        const wxPoint& pos = wxDefaultPosition,
 289                        const wxSize& size = wxDefaultSize,
 290                        long style = wxHD_DEFAULT_STYLE,
 291                        const wxString& name = wxHeaderCtrlNameStr);
 292
 293     /**
 294         Insert the column at the given position.
 295
 296         @param col
 297             The column to insert. Notice that because of the existence of
 298             implicit conversion from wxString to wxHeaderColumn a string
 299             can be passed directly here.
 300         @param idx
 301             The position of the new column, from 0 to GetColumnCount(). Using
 302             GetColumnCount() means to append the column to the end.
 303
 304         @see AppendColumn()
 305      */
 306     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 307
 308     /**
 309         Append the column to the end of the control.
 310
 311         @see InsertColumn()
 312      */
 313     void AppendColumn(const wxHeaderColumn& col);
 314
 315     /**
 316         Delete the column at the given position.
 317
 318         @see InsertColumn(), AppendColumn()
 319      */
 320     void DeleteColumn(unsigned int idx);
 321
 322     /**
 323         Show or hide the column.
 324
 325         Initially the column is shown by default or hidden if it was added with
 326         wxCOL_HIDDEN flag set.
 327
 328         When a column is hidden, it doesn't appear at all on the screen but its
 329         index is still taken into account when working with other columns. E.g.
 330         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 331         still need to use index 2 to refer to the last visible column.
 332
 333         @param idx
 334             The index of the column to show or hide, from 0 to GetColumnCount().
 335         @param show
 336             Indicates whether the column should be shown (default) or hidden.
 337      */
 338     void ShowColumn(unsigned int idx, bool show = true);
 339
 340     /**
 341         Hide the column with the given index.
 342
 343         This is the same as calling @code ShowColumn(idx, false) @endcode.
 344
 345         @param idx
 346             The index of the column to show or hide, from 0 to GetColumnCount().
 347      */
 348     void HideColumn(unsigned int idx);
 349
 350     /**
 351         Update the column sort indicator.
 352
 353         The sort indicator, if shown, is typically an arrow pointing upwards or
 354         downwards depending on whether the control contents is sorted in
 355         ascending or descending order.
 356
 357         @param idx
 358             The column to set the sort indicator for.
 359         @param sortOrder
 360             If @true or @false show the sort indicator corresponding to
 361             ascending or descending sort order respectively, if @c -1 remove
 362             the currently shown sort indicator.
 363      */
 364     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 365
 366     /**
 367         Remove the sort indicator from the given column.
 368
 369         This is the same as calling ShowSortIndicator() with @c -1 argument.
 370
 371         @param idx
 372             The column to remove sort indicator for.
 373      */
 374     void RemoveSortIndicator(unsigned int idx);
 375
 376 protected:
 377     /**
 378         This function can be overridden in the classes deriving from this
 379         control instead of overriding UpdateColumnWidthToFit().
 380
 381         To implement automatic column resizing to fit its contents width when
 382         the column divider is double clicked, you need to simply return the
 383         fitting width for the given column @a idx from this method, the control
 384         will automatically use the biggest value between the one returned from
 385         here and the one needed for the display of the column title itself.
 386
 387         The base class version returns -1 indicating that this function is not
 388         implemented.
 389      */
 390     virtual int GetBestFittingWidth(unsigned int idx) const;
 391 };
 392
 393 /**
 394     @class wxHeaderCtrlEvent
 395
 396     Event class representing the events generated by wxHeaderCtrl.
 397
 398     @library{wxcore}
 399     @category{ctrl}
 400
 401     @see wxHeaderCtrl
 402 */
 403 class wxHeaderCtrlEvent : public wxNotifyEvent
 404 {
 405 public:
 406     /**
 407         Return the index of the column affected by this event.
 408
 409         This method can be called for all header control events.
 410      */
 411     int GetColumn() const;
 412
 413     /**
 414         Return the current width of the column.
 415
 416         This method can only be called for the dragging events.
 417      */
 418     int GetWidth() const;
 419
 420     /**
 421         Return @true if the drag operation was cancelled.
 422
 423         This method can only be called for the end drag event.
 424      */
 425     bool IsCancelled() const;
 426 };