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 (or dragging cancelled) events will be
  79             generated later.
  80         @event{EVT_HEADER_RESIZING(id, func)}
  81             The user is dragging the column with the specified index resizing
  82             it and its current width is wxHeaderCtrlEvent::GetWidth(). The
  83             event can be vetoed to stop the dragging operation completely at
  84             any time.
  85         @event{EVT_HEADER_END_RESIZE(id, func)}
  86             The user stopped dragging the column by releasing the mouse. The
  87             column should normally be resized to the value of
  88             wxHeaderCtrlEvent::GetWidth().
  89
  90         @event{EVT_HEADER_BEGIN_REORDER(id, func)}
  91             The user started to drag the column with the specified index (this
  92             can only happen for the controls with wxHD_DRAGDROP style). This
  93             event can be vetoed to prevent the column from being reordered,
  94             otherwise the end reorder message will be generated later.
  95         @event{EVT_HEADER_END_REORDER(id, func)}
  96             The user dropped the column in its new location. The event can be
  97             vetoed to prevent the column from being placed at the new position
  98             or handled to update the display of the data in the associated
  99             control to match the new column location (available from
 100             wxHeaderCtrlEvent::GetNewOrder()).
 101
 102         @event{EVT_HEADER_DRAGGING_CANCELLED(id, func)}
 103             The resizing or reordering operation currently in progress was
 104             cancelled. This can happen if the user pressed Esc key while
 105             dragging the mouse or the mouse capture was lost for some other
 106             reason. You only need to handle this event if your application
 107             entered into some modal mode when resizing or reordering began, in
 108             which case it should handle this event in addition to the matching
 109             end resizing or reordering ones.
 110     @endEventTable
 111
 112     @library{wxcore}
 113     @category{ctrl}
 114
 115     @see wxGrid, wxListCtrl, wxDataViewCtrl
 116
 117
 118     @section headerctrl_improvements Future Improvements
 119
 120     Some features are supported by the native MSW control and so could be
 121     easily implemented in this version of wxHeaderCtrl but need to be
 122     implemented in the generic version as well to be really useful. Please let
 123     us know if you need or, better, plan to work on implementing, any of them:
 124         - Displaying bitmaps instead of or together with the text
 125         - Custom drawn headers
 126         - Filters associated with a column.
 127 */
 128 class wxHeaderCtrl
 129 {
 130 public:
 131     /**
 132         Default constructor not creating the underlying window.
 133
 134         You must use Create() after creating the object using this constructor.
 135      */
 136     wxHeaderCtrl();
 137
 138     /**
 139         Constructor creating the window.
 140
 141         Please see Create() for the parameters documentation.
 142      */
 143     wxHeaderCtrl(wxWindow *parent,
 144                  wxWindowID winid = wxID_ANY,
 145                  const wxPoint& pos = wxDefaultPosition,
 146                  const wxSize& size = wxDefaultSize,
 147                  long style = wxHD_DEFAULT_STYLE,
 148                  const wxString& name = wxHeaderCtrlNameStr);
 149
 150     /**
 151         Create the header control window.
 152
 153         @param parent
 154             The parent window. The header control should be typically
 155             positioned along the top edge of this window.
 156         @param winid
 157             Id of the control or @c wxID_ANY if you don't care.
 158         @param pos
 159             The initial position of the control.
 160         @param size
 161             The initial size of the control (usually not very useful as this
 162             control will typically be resized to have the same width as the
 163             associated data display control).
 164         @param style
 165             The control style, @c wxHD_DEFAULT_STYLE by default. Notice that
 166             the default style allows the user to reorder the columns by
 167             dragging them and you need to explicitly turn this feature off by
 168             using @code wxHD_DEFAULT_STYLE & ~wxHD_DRAGDROP @endcode if this is
 169             undesirable.
 170         @param name
 171             The name of the control.
 172      */
 173     bool Create(wxWindow *parent,
 174                 wxWindowID winid = wxID_ANY,
 175                 const wxPoint& pos = wxDefaultPosition,
 176                 const wxSize& size = wxDefaultSize,
 177                 long style = wxHD_DEFAULT_STYLE,
 178                 const wxString& name = wxHeaderCtrlNameStr);
 179
 180     /**
 181         Set the number of columns in the control.
 182
 183         The control will use GetColumn() to get information about all the
 184         new columns and refresh itself, i.e. this method also has the same
 185         effect as calling UpdateColumn() for all columns but it should only be
 186         used if the number of columns really changed.
 187      */
 188     void SetColumnCount(unsigned int count);
 189
 190     /**
 191         Return the number of columns in the control.
 192
 193         @return
 194             Number of columns as previously set by SetColumnCount().
 195
 196         @see IsEmpty()
 197      */
 198     unsigned int GetColumnCount() const;
 199
 200     /**
 201         Return whether the control has any columns.
 202
 203         @see GetColumnCount()
 204      */
 205     bool IsEmpty() const;
 206
 207     /**
 208         Update the column with the given index.
 209
 210         When the value returned by GetColumn() changes, this method must be
 211         called to notify the control about the change and update the visual
 212         display to match the new column data.
 213
 214         @param idx
 215             The column index, must be less than GetColumnCount().
 216      */
 217     void UpdateColumn(unsigned int idx);
 218
 219     /**
 220         Change the columns display order.
 221
 222         The display order defines the order in which the columns appear on the
 223         screen and does @em not affect the interpretation of indices by all the
 224         other class methods.
 225
 226         The @a order array specifies the column indices corresponding to the
 227         display positions.
 228
 229         @param order
 230             A permutation of all column indices, i.e. an array of size
 231             GetColumnsOrder() containing all column indices exactly once. The
 232             n-th element of this array defines the index of the column shown at
 233             the n-th position from left (for the default left-to-right writing
 234             direction).
 235
 236         @see wxListCtrl::SetColumnsOrder()
 237      */
 238     void SetColumnsOrder(const wxArrayInt& order);
 239
 240     /**
 241         Return the array describing the columns display order.
 242
 243         For the controls without wxHD_DRAGDROP style the returned array will be
 244         the same as was passed to SetColumnsOrder() previously or define the
 245         default order (with n-th element being n) if it hadn't been called. But
 246         for the controls with wxHD_DRAGDROP style, the columns can be also
 247         reordered by user.
 248      */
 249     wxArrayInt GetColumnsOrder() const;
 250
 251     /**
 252         Return the index of the column displayed at the given position.
 253
 254         @param pos
 255             The display position, e.g. 0 for the left-most column, 1 for the
 256             next one and so on until GetColumnCount() - 1.
 257
 258         @see GetColumnPos()
 259      */
 260     unsigned int GetColumnAt(unsigned int pos) const;
 261
 262     /**
 263         Get the position at which this column is currently displayed.
 264
 265         Notice that a valid position is returned even for the hidden columns
 266         currently.
 267
 268         @param idx
 269             The column index, must be less than GetColumnCount().
 270
 271         @see GetColumnAt()
 272      */
 273     unsigned int GetColumnPos(unsigned int idx) const;
 274
 275 protected:
 276     /**
 277         Method to be implemented by the derived classes to return the
 278         information for the given column.
 279
 280         @param idx
 281             The column index, between 0 and the value last passed to
 282             SetColumnCount().
 283      */
 284     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 285
 286     /**
 287         Method which may be implemented by the derived classes to allow double
 288         clicking the column separator to resize the column to fit its contents.
 289
 290         When a separator is double clicked, the default handler of
 291         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 292         column if it returns @true so to implement the resizing of the column
 293         to fit its width on header double click you need to implement this
 294         method using logic similar to this example:
 295         @code
 296             class MyHeaderCtrl : public wxHeaderColumnBase
 297             {
 298             public:
 299                 ...
 300
 301                 void SetWidth(int width) { m_width = width; }
 302                 virtual int GetWidth() const { return m_width; }
 303
 304             private:
 305                 int m_width;
 306             };
 307
 308             class MyHeaderCtrl : public wxHeaderCtrl
 309             {
 310             public:
 311             protected:
 312                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 313                 {
 314                     return m_cols[idx];
 315                 }
 316
 317                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 318                 {
 319                     int widthContents = ... compute minimal width for column idx ...
 320                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 321                     return true;
 322                 }
 323
 324                 wxVector<MyHeaderColumn> m_cols;
 325             };
 326         @endcode
 327
 328         Base class version simply returns @false.
 329
 330         @param width
 331             Contains minimal width needed to display the column header itself
 332             and will usually be used as a starting point for the fitting width
 333             calculation.
 334         @return
 335             @true to indicate that the column was resized, i.e. GetColumn() now
 336             returns the new width value, and so must be refreshed or @false
 337             meaning that the control didn't reach to the separator double click.
 338      */
 339     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 340
 341     /**
 342         Can be overridden in the derived class to update internal data
 343         structures when the number of the columns in the control changes.
 344
 345         This method is called by SetColumnCount() before effectively changing
 346         the number of columns.
 347
 348         The base class version does nothing but it is good practice to still
 349         call it from the overridden version in the derived class.
 350      */
 351     virtual void OnColumnCountChanging(unsigned int count);
 352 };
 353
 354
 355 /**
 356     @class wxHeaderCtrlSimple
 357
 358     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 359     without inheriting from it as you need to do when using wxHeaderCtrl
 360     itself.
 361
 362     When using it, you need to use simple AppendColumn(), InsertColumn() and
 363     DeleteColumn() methods instead of setting the number of columns with
 364     SetColumnCount() and returning the information about them from the
 365     overridden GetColumn().
 366
 367     @library{wxcore}
 368     @category{ctrl}
 369
 370     @see wxHeaderCtrl
 371 */
 372 class wxHeaderCtrlSimple : public wxHeaderCtrl
 373 {
 374 public:
 375     /**
 376         Default constructor not creating the underlying window.
 377
 378         You must use Create() after creating the object using this constructor.
 379      */
 380     wxHeaderCtrlSimple();
 381
 382     /**
 383         Constructor creating the window.
 384
 385         Please see the base class wxHeaderCtrl::Create() method for the
 386         parameters description.
 387      */
 388     wxHeaderCtrlSimple(wxWindow *parent,
 389                        wxWindowID winid = wxID_ANY,
 390                        const wxPoint& pos = wxDefaultPosition,
 391                        const wxSize& size = wxDefaultSize,
 392                        long style = wxHD_DEFAULT_STYLE,
 393                        const wxString& name = wxHeaderCtrlNameStr);
 394
 395     /**
 396         Insert the column at the given position.
 397
 398         @param col
 399             The column to insert. Notice that because of the existence of
 400             implicit conversion from wxString to wxHeaderColumn a string
 401             can be passed directly here.
 402         @param idx
 403             The position of the new column, from 0 to GetColumnCount(). Using
 404             GetColumnCount() means to append the column to the end.
 405
 406         @see AppendColumn()
 407      */
 408     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 409
 410     /**
 411         Append the column to the end of the control.
 412
 413         @see InsertColumn()
 414      */
 415     void AppendColumn(const wxHeaderColumn& col);
 416
 417     /**
 418         Delete the column at the given position.
 419
 420         @see InsertColumn(), AppendColumn()
 421      */
 422     void DeleteColumn(unsigned int idx);
 423
 424     /**
 425         Show or hide the column.
 426
 427         Initially the column is shown by default or hidden if it was added with
 428         wxCOL_HIDDEN flag set.
 429
 430         When a column is hidden, it doesn't appear at all on the screen but its
 431         index is still taken into account when working with other columns. E.g.
 432         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 433         still need to use index 2 to refer to the last visible column.
 434
 435         @param idx
 436             The index of the column to show or hide, from 0 to GetColumnCount().
 437         @param show
 438             Indicates whether the column should be shown (default) or hidden.
 439      */
 440     void ShowColumn(unsigned int idx, bool show = true);
 441
 442     /**
 443         Hide the column with the given index.
 444
 445         This is the same as calling @code ShowColumn(idx, false) @endcode.
 446
 447         @param idx
 448             The index of the column to show or hide, from 0 to GetColumnCount().
 449      */
 450     void HideColumn(unsigned int idx);
 451
 452     /**
 453         Update the column sort indicator.
 454
 455         The sort indicator, if shown, is typically an arrow pointing upwards or
 456         downwards depending on whether the control contents is sorted in
 457         ascending or descending order.
 458
 459         @param idx
 460             The column to set the sort indicator for.
 461         @param sortOrder
 462             If @true or @false show the sort indicator corresponding to
 463             ascending or descending sort order respectively, if @c -1 remove
 464             the currently shown sort indicator.
 465      */
 466     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 467
 468     /**
 469         Remove the sort indicator from the given column.
 470
 471         This is the same as calling ShowSortIndicator() with @c -1 argument.
 472
 473         @param idx
 474             The column to remove sort indicator for.
 475      */
 476     void RemoveSortIndicator(unsigned int idx);
 477
 478 protected:
 479     /**
 480         This function can be overridden in the classes deriving from this
 481         control instead of overriding UpdateColumnWidthToFit().
 482
 483         To implement automatic column resizing to fit its contents width when
 484         the column divider is double clicked, you need to simply return the
 485         fitting width for the given column @a idx from this method, the control
 486         will automatically use the biggest value between the one returned from
 487         here and the one needed for the display of the column title itself.
 488
 489         The base class version returns -1 indicating that this function is not
 490         implemented.
 491      */
 492     virtual int GetBestFittingWidth(unsigned int idx) const;
 493 };
 494
 495 /**
 496     @class wxHeaderCtrlEvent
 497
 498     Event class representing the events generated by wxHeaderCtrl.
 499
 500     @library{wxcore}
 501     @category{ctrl}
 502
 503     @see wxHeaderCtrl
 504 */
 505 class wxHeaderCtrlEvent : public wxNotifyEvent
 506 {
 507 public:
 508     /**
 509         Return the index of the column affected by this event.
 510
 511         This method can be called for all header control events.
 512      */
 513     int GetColumn() const;
 514
 515     /**
 516         Return the current width of the column.
 517
 518         This method can only be called for the dragging events.
 519      */
 520     int GetWidth() const;
 521
 522     /**
 523         Return the new order of the column.
 524
 525         This method can only be called for end reorder event for which it
 526         indicates the tentative new position for the column GetColumn()
 527         selected by the user. If the event is not vetoed, this will become the
 528         new column position in wxHeaderCtrl::GetColumnsOrder().
 529      */
 530     unsigned int GetNewOrder() const;
 531 };