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     /**
 187         Update the column with the given index.
 188
 189         When the value returned by GetColumn() changes, this method must be
 190         called to notify the control about the change and update the visual
 191         display to match the new column data.
 192
 193         @param idx
 194             The column index, must be less than GetColumnCount().
 195      */
 196     void UpdateColumn(unsigned int idx);
 197
 198 protected:
 199     /**
 200         Method to be implemented by the derived classes to return the
 201         information for the given column.
 202
 203         @param idx
 204             The column index, between 0 and the value last passed to
 205             SetColumnCount().
 206      */
 207     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 208
 209     /**
 210         Method which may be implemented by the derived classes to allow double
 211         clicking the column separator to resize the column to fit its contents.
 212
 213         When a separator is double clicked, the default handler of
 214         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 215         column if it returns @true so to implement the resizing of the column
 216         to fit its width on header double click you need to implement this
 217         method using logic similar to this example:
 218         @code
 219             class MyHeaderCtrl : public wxHeaderColumnBase
 220             {
 221             public:
 222                 ...
 223
 224                 void SetWidth(int width) { m_width = width; }
 225                 virtual int GetWidth() const { return m_width; }
 226
 227             private:
 228                 int m_width;
 229             };
 230
 231             class MyHeaderCtrl : public wxHeaderCtrl
 232             {
 233             public:
 234             protected:
 235                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 236                 {
 237                     return m_cols[idx];
 238                 }
 239
 240                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 241                 {
 242                     int widthContents = ... compute minimal width for column idx ...
 243                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 244                     return true;
 245                 }
 246
 247                 wxVector<MyHeaderColumn> m_cols;
 248             };
 249         @endcode
 250
 251         Base class version simply returns @false.
 252
 253         @param width
 254             Contains minimal width needed to display the column header itself
 255             and will usually be used as a starting point for the fitting width
 256             calculation.
 257         @return
 258             @true to indicate that the column was resized, i.e. GetColumn() now
 259             returns the new width value, and so must be refreshed or @false
 260             meaning that the control didn't reach to the separator double click.
 261      */
 262     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 263 };
 264
 265
 266 /**
 267     @class wxHeaderCtrlSimple
 268
 269     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 270     without inheriting from it as you need to do when using wxHeaderCtrl
 271     itself.
 272
 273     When using it, you need to use simple AppendColumn(), InsertColumn() and
 274     DeleteColumn() methods instead of setting the number of columns with
 275     SetColumnCount() and returning the information about them from the
 276     overridden GetColumn().
 277
 278     @library{wxcore}
 279     @category{ctrl}
 280
 281     @see wxHeaderCtrl
 282 */
 283 class wxHeaderCtrlSimple : public wxHeaderCtrl
 284 {
 285 public:
 286     /**
 287         Default constructor not creating the underlying window.
 288
 289         You must use Create() after creating the object using this constructor.
 290      */
 291     wxHeaderCtrlSimple();
 292
 293     /**
 294         Constructor creating the window.
 295
 296         Please see the base class wxHeaderCtrl::Create() method for the
 297         parameters description.
 298      */
 299     wxHeaderCtrlSimple(wxWindow *parent,
 300                        wxWindowID winid = wxID_ANY,
 301                        const wxPoint& pos = wxDefaultPosition,
 302                        const wxSize& size = wxDefaultSize,
 303                        long style = wxHD_DEFAULT_STYLE,
 304                        const wxString& name = wxHeaderCtrlNameStr);
 305
 306     /**
 307         Insert the column at the given position.
 308
 309         @param col
 310             The column to insert. Notice that because of the existence of
 311             implicit conversion from wxString to wxHeaderColumn a string
 312             can be passed directly here.
 313         @param idx
 314             The position of the new column, from 0 to GetColumnCount(). Using
 315             GetColumnCount() means to append the column to the end.
 316
 317         @see AppendColumn()
 318      */
 319     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 320
 321     /**
 322         Append the column to the end of the control.
 323
 324         @see InsertColumn()
 325      */
 326     void AppendColumn(const wxHeaderColumn& col);
 327
 328     /**
 329         Delete the column at the given position.
 330
 331         @see InsertColumn(), AppendColumn()
 332      */
 333     void DeleteColumn(unsigned int idx);
 334
 335     /**
 336         Show or hide the column.
 337
 338         Initially the column is shown by default or hidden if it was added with
 339         wxCOL_HIDDEN flag set.
 340
 341         When a column is hidden, it doesn't appear at all on the screen but its
 342         index is still taken into account when working with other columns. E.g.
 343         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 344         still need to use index 2 to refer to the last visible column.
 345
 346         @param idx
 347             The index of the column to show or hide, from 0 to GetColumnCount().
 348         @param show
 349             Indicates whether the column should be shown (default) or hidden.
 350      */
 351     void ShowColumn(unsigned int idx, bool show = true);
 352
 353     /**
 354         Hide the column with the given index.
 355
 356         This is the same as calling @code ShowColumn(idx, false) @endcode.
 357
 358         @param idx
 359             The index of the column to show or hide, from 0 to GetColumnCount().
 360      */
 361     void HideColumn(unsigned int idx);
 362
 363     /**
 364         Update the column sort indicator.
 365
 366         The sort indicator, if shown, is typically an arrow pointing upwards or
 367         downwards depending on whether the control contents is sorted in
 368         ascending or descending order.
 369
 370         @param idx
 371             The column to set the sort indicator for.
 372         @param sortOrder
 373             If @true or @false show the sort indicator corresponding to
 374             ascending or descending sort order respectively, if @c -1 remove
 375             the currently shown sort indicator.
 376      */
 377     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 378
 379     /**
 380         Remove the sort indicator from the given column.
 381
 382         This is the same as calling ShowSortIndicator() with @c -1 argument.
 383
 384         @param idx
 385             The column to remove sort indicator for.
 386      */
 387     void RemoveSortIndicator(unsigned int idx);
 388
 389 protected:
 390     /**
 391         This function can be overridden in the classes deriving from this
 392         control instead of overriding UpdateColumnWidthToFit().
 393
 394         To implement automatic column resizing to fit its contents width when
 395         the column divider is double clicked, you need to simply return the
 396         fitting width for the given column @a idx from this method, the control
 397         will automatically use the biggest value between the one returned from
 398         here and the one needed for the display of the column title itself.
 399
 400         The base class version returns -1 indicating that this function is not
 401         implemented.
 402      */
 403     virtual int GetBestFittingWidth(unsigned int idx) const;
 404 };
 405
 406 /**
 407     @class wxHeaderCtrlEvent
 408
 409     Event class representing the events generated by wxHeaderCtrl.
 410
 411     @library{wxcore}
 412     @category{ctrl}
 413
 414     @see wxHeaderCtrl
 415 */
 416 class wxHeaderCtrlEvent : public wxNotifyEvent
 417 {
 418 public:
 419     /**
 420         Return the index of the column affected by this event.
 421
 422         This method can be called for all header control events.
 423      */
 424     int GetColumn() const;
 425
 426     /**
 427         Return the current width of the column.
 428
 429         This method can only be called for the dragging events.
 430      */
 431     int GetWidth() const;
 432
 433     /**
 434         Return @true if the drag operation was cancelled.
 435
 436         This method can only be called for the end drag event.
 437      */
 438     bool IsCancelled() const;
 439 };