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_RESIZE(id, func)}
  74             The user started to drag the separator to the right of the column
  75             with the specified index (this can only happen for the columns for
  76             which wxHeaderColumn::IsResizeable() returns true). The event can
  77             be vetoed to prevent the column from being resized. If it isn't,
  78             the resizing and end resize events will be generated later.
  79         @event{EVT_HEADER_RESIZING(id, func)}
  80             The user is dragging the column with the specified index resizing
  81             it and its current width is wxHeaderCtrlEvent::GetWidth(). The
  82             event can be vetoed to stop the dragging operation completely at
  83             any time.
  84         @event{EVT_HEADER_END_RESIZE(id, func)}
  85             Either the user stopped dragging the column by releasing the mouse
  86             or the resizing was cancelled. If wxHeaderCtrlEvent::IsCancelled()
  87             returns @true, nothing should be done, otherwise the column should
  88             normally be resized to the value of wxHeaderCtrlEvent::GetWidth().
  89     @endEventTable
  90
  91     @library{wxcore}
  92     @category{ctrl}
  93
  94     @see wxGrid, wxListCtrl, wxDataViewCtrl
  95
  96
  97     @section headerctrl_improvements Future Improvements
  98
  99     Some features are supported by the native MSW control and so could be
 100     easily implemented in this version of wxHeaderCtrl but need to be
 101     implemented in the generic version as well to be really useful. Please let
 102     us know if you need or, better, plan to work on implementing, any of them:
 103         - Displaying bitmaps instead of or together with the text
 104         - Custom drawn headers
 105         - Filters associated with a column.
 106 */
 107 class wxHeaderCtrl
 108 {
 109 public:
 110     /**
 111         Default constructor not creating the underlying window.
 112
 113         You must use Create() after creating the object using this constructor.
 114      */
 115     wxHeaderCtrl();
 116
 117     /**
 118         Constructor creating the window.
 119
 120         Please see Create() for the parameters documentation.
 121      */
 122     wxHeaderCtrl(wxWindow *parent,
 123                  wxWindowID winid = wxID_ANY,
 124                  const wxPoint& pos = wxDefaultPosition,
 125                  const wxSize& size = wxDefaultSize,
 126                  long style = wxHD_DEFAULT_STYLE,
 127                  const wxString& name = wxHeaderCtrlNameStr);
 128
 129     /**
 130         Create the header control window.
 131
 132         @param parent
 133             The parent window. The header control should be typically
 134             positioned along the top edge of this window.
 135         @param winid
 136             Id of the control or @c wxID_ANY if you don't care.
 137         @param pos
 138             The initial position of the control.
 139         @param size
 140             The initial size of the control (usually not very useful as this
 141             control will typically be resized to have the same width as the
 142             associated data display control).
 143         @param style
 144             The control style, @c wxHD_DEFAULT_STYLE by default. Notice that
 145             the default style allows the user to reorder the columns by
 146             dragging them and you need to explicitly turn this feature off by
 147             using @code wxHD_DEFAULT_STYLE & ~wxHD_DRAGDROP @endcode if this is
 148             undesirable.
 149         @param name
 150             The name of the control.
 151      */
 152     bool Create(wxWindow *parent,
 153                 wxWindowID winid = wxID_ANY,
 154                 const wxPoint& pos = wxDefaultPosition,
 155                 const wxSize& size = wxDefaultSize,
 156                 long style = wxHD_DEFAULT_STYLE,
 157                 const wxString& name = wxHeaderCtrlNameStr);
 158
 159     /**
 160         Set the number of columns in the control.
 161
 162         The control will use GetColumn() to get information about all the
 163         new columns and refresh itself, i.e. this method also has the same
 164         effect as calling UpdateColumn() for all columns but it should only be
 165         used if the number of columns really changed.
 166      */
 167     void SetColumnCount(unsigned int count);
 168
 169     /**
 170         Return the number of columns in the control.
 171
 172         @return
 173             Number of columns as previously set by SetColumnCount().
 174
 175         @see IsEmpty()
 176      */
 177     unsigned int GetColumnCount() const;
 178
 179     /**
 180         Return whether the control has any columns.
 181
 182         @see GetColumnCount()
 183      */
 184     bool IsEmpty() const;
 185
 186 protected:
 187     /**
 188         Method to be implemented by the derived classes to return the
 189         information for the given column.
 190
 191         @param idx
 192             The column index, between 0 and the value last passed to
 193             SetColumnCount().
 194      */
 195     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 196
 197     /**
 198         Method which may be implemented by the derived classes to allow double
 199         clicking the column separator to resize the column to fit its contents.
 200
 201         When a separator is double clicked, the default handler of
 202         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 203         column if it returns @true so to implement the resizing of the column
 204         to fit its width on header double click you need to implement this
 205         method using logic similar to this example:
 206         @code
 207             class MyHeaderCtrl : public wxHeaderColumnBase
 208             {
 209             public:
 210                 ...
 211
 212                 void SetWidth(int width) { m_width = width; }
 213                 virtual int GetWidth() const { return m_width; }
 214
 215             private:
 216                 int m_width;
 217             };
 218
 219             class MyHeaderCtrl : public wxHeaderCtrl
 220             {
 221             public:
 222             protected:
 223                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 224                 {
 225                     return m_cols[idx];
 226                 }
 227
 228                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 229                 {
 230                     int widthContents = ... compute minimal width for column idx ...
 231                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 232                     return true;
 233                 }
 234
 235                 wxVector<MyHeaderColumn> m_cols;
 236             };
 237         @endcode
 238
 239         Base class version simply returns @false.
 240
 241         @param width
 242             Contains minimal width needed to display the column header itself
 243             and will usually be used as a starting point for the fitting width
 244             calculation.
 245         @return
 246             @true to indicate that the column was resized, i.e. GetColumn() now
 247             returns the new width value, and so must be refreshed or @false
 248             meaning that the control didn't reach to the separator double click.
 249      */
 250     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 251 };
 252
 253
 254 /**
 255     @class wxHeaderCtrlSimple
 256
 257     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 258     without inheriting from it as you need to do when using wxHeaderCtrl
 259     itself.
 260
 261     When using it, you need to use simple AppendColumn(), InsertColumn() and
 262     DeleteColumn() methods instead of setting the number of columns with
 263     SetColumnCount() and returning the information about them from the
 264     overridden GetColumn().
 265
 266     @library{wxcore}
 267     @category{ctrl}
 268
 269     @see wxHeaderCtrl
 270 */
 271 class wxHeaderCtrlSimple : public wxHeaderCtrl
 272 {
 273 public:
 274     /**
 275         Default constructor not creating the underlying window.
 276
 277         You must use Create() after creating the object using this constructor.
 278      */
 279     wxHeaderCtrlSimple();
 280
 281     /**
 282         Constructor creating the window.
 283
 284         Please see the base class wxHeaderCtrl::Create() method for the
 285         parameters description.
 286      */
 287     wxHeaderCtrlSimple(wxWindow *parent,
 288                        wxWindowID winid = wxID_ANY,
 289                        const wxPoint& pos = wxDefaultPosition,
 290                        const wxSize& size = wxDefaultSize,
 291                        long style = wxHD_DEFAULT_STYLE,
 292                        const wxString& name = wxHeaderCtrlNameStr);
 293
 294     /**
 295         Insert the column at the given position.
 296
 297         @param col
 298             The column to insert. Notice that because of the existence of
 299             implicit conversion from wxString to wxHeaderColumn a string
 300             can be passed directly here.
 301         @param idx
 302             The position of the new column, from 0 to GetColumnCount(). Using
 303             GetColumnCount() means to append the column to the end.
 304
 305         @see AppendColumn()
 306      */
 307     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 308
 309     /**
 310         Append the column to the end of the control.
 311
 312         @see InsertColumn()
 313      */
 314     void AppendColumn(const wxHeaderColumn& col);
 315
 316     /**
 317         Delete the column at the given position.
 318
 319         @see InsertColumn(), AppendColumn()
 320      */
 321     void DeleteColumn(unsigned int idx);
 322
 323     /**
 324         Show or hide the column.
 325
 326         Initially the column is shown by default or hidden if it was added with
 327         wxCOL_HIDDEN flag set.
 328
 329         When a column is hidden, it doesn't appear at all on the screen but its
 330         index is still taken into account when working with other columns. E.g.
 331         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 332         still need to use index 2 to refer to the last visible column.
 333
 334         @param idx
 335             The index of the column to show or hide, from 0 to GetColumnCount().
 336         @param show
 337             Indicates whether the column should be shown (default) or hidden.
 338      */
 339     void ShowColumn(unsigned int idx, bool show = true);
 340
 341     /**
 342         Hide the column with the given index.
 343
 344         This is the same as calling @code ShowColumn(idx, false) @endcode.
 345
 346         @param idx
 347             The index of the column to show or hide, from 0 to GetColumnCount().
 348      */
 349     void HideColumn(unsigned int idx);
 350
 351     /**
 352         Update the column sort indicator.
 353
 354         The sort indicator, if shown, is typically an arrow pointing upwards or
 355         downwards depending on whether the control contents is sorted in
 356         ascending or descending order.
 357
 358         @param idx
 359             The column to set the sort indicator for.
 360         @param sortOrder
 361             If @true or @false show the sort indicator corresponding to
 362             ascending or descending sort order respectively, if @c -1 remove
 363             the currently shown sort indicator.
 364      */
 365     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 366
 367     /**
 368         Remove the sort indicator from the given column.
 369
 370         This is the same as calling ShowSortIndicator() with @c -1 argument.
 371
 372         @param idx
 373             The column to remove sort indicator for.
 374      */
 375     void RemoveSortIndicator(unsigned int idx);
 376
 377 protected:
 378     /**
 379         This function can be overridden in the classes deriving from this
 380         control instead of overriding UpdateColumnWidthToFit().
 381
 382         To implement automatic column resizing to fit its contents width when
 383         the column divider is double clicked, you need to simply return the
 384         fitting width for the given column @a idx from this method, the control
 385         will automatically use the biggest value between the one returned from
 386         here and the one needed for the display of the column title itself.
 387
 388         The base class version returns -1 indicating that this function is not
 389         implemented.
 390      */
 391     virtual int GetBestFittingWidth(unsigned int idx) const;
 392 };
 393
 394 /**
 395     @class wxHeaderCtrlEvent
 396
 397     Event class representing the events generated by wxHeaderCtrl.
 398
 399     @library{wxcore}
 400     @category{ctrl}
 401
 402     @see wxHeaderCtrl
 403 */
 404 class wxHeaderCtrlEvent : public wxNotifyEvent
 405 {
 406 public:
 407     /**
 408         Return the index of the column affected by this event.
 409
 410         This method can be called for all header control events.
 411      */
 412     int GetColumn() const;
 413
 414     /**
 415         Return the current width of the column.
 416
 417         This method can only be called for the dragging events.
 418      */
 419     int GetWidth() const;
 420
 421     /**
 422         Return @true if the drag operation was cancelled.
 423
 424         This method can only be called for the end drag event.
 425      */
 426     bool IsCancelled() const;
 427 };