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     /**
 276         Helper function to manipulate the array of column indices.
 277
 278         This function reshuffles the array of column indices indexed by
 279         positions (i.e. using the same convention as for SetColumnsOrder()) so
 280         that the column with the given index is found at the specified
 281         position.
 282
 283         @param order
 284             Array containing the indices of columns in order of their
 285             positions.
 286         @param idx
 287             The index of the column to move.
 288         @param pos
 289             The new position for the column @a idx.
 290      */
 291     static void MoveColumnInOrderArray(wxArrayInt& order,
 292                                        unsigned int idx,
 293                                        unsigned int pos);
 294
 295 protected:
 296     /**
 297         Method to be implemented by the derived classes to return the
 298         information for the given column.
 299
 300         @param idx
 301             The column index, between 0 and the value last passed to
 302             SetColumnCount().
 303      */
 304     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 305
 306     /**
 307         Method which may be implemented by the derived classes to allow double
 308         clicking the column separator to resize the column to fit its contents.
 309
 310         When a separator is double clicked, the default handler of
 311         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 312         column if it returns @true so to implement the resizing of the column
 313         to fit its width on header double click you need to implement this
 314         method using logic similar to this example:
 315         @code
 316             class MyHeaderCtrl : public wxHeaderColumnBase
 317             {
 318             public:
 319                 ...
 320
 321                 void SetWidth(int width) { m_width = width; }
 322                 virtual int GetWidth() const { return m_width; }
 323
 324             private:
 325                 int m_width;
 326             };
 327
 328             class MyHeaderCtrl : public wxHeaderCtrl
 329             {
 330             public:
 331             protected:
 332                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 333                 {
 334                     return m_cols[idx];
 335                 }
 336
 337                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 338                 {
 339                     int widthContents = ... compute minimal width for column idx ...
 340                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 341                     return true;
 342                 }
 343
 344                 wxVector<MyHeaderColumn> m_cols;
 345             };
 346         @endcode
 347
 348         Base class version simply returns @false.
 349
 350         @param width
 351             Contains minimal width needed to display the column header itself
 352             and will usually be used as a starting point for the fitting width
 353             calculation.
 354         @return
 355             @true to indicate that the column was resized, i.e. GetColumn() now
 356             returns the new width value, and so must be refreshed or @false
 357             meaning that the control didn't reach to the separator double click.
 358      */
 359     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 360
 361     /**
 362         Can be overridden in the derived class to update internal data
 363         structures when the number of the columns in the control changes.
 364
 365         This method is called by SetColumnCount() before effectively changing
 366         the number of columns.
 367
 368         The base class version does nothing but it is good practice to still
 369         call it from the overridden version in the derived class.
 370      */
 371     virtual void OnColumnCountChanging(unsigned int count);
 372 };
 373
 374
 375 /**
 376     @class wxHeaderCtrlSimple
 377
 378     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 379     without inheriting from it as you need to do when using wxHeaderCtrl
 380     itself.
 381
 382     When using it, you need to use simple AppendColumn(), InsertColumn() and
 383     DeleteColumn() methods instead of setting the number of columns with
 384     SetColumnCount() and returning the information about them from the
 385     overridden GetColumn().
 386
 387     @library{wxcore}
 388     @category{ctrl}
 389
 390     @see wxHeaderCtrl
 391 */
 392 class wxHeaderCtrlSimple : public wxHeaderCtrl
 393 {
 394 public:
 395     /**
 396         Default constructor not creating the underlying window.
 397
 398         You must use Create() after creating the object using this constructor.
 399      */
 400     wxHeaderCtrlSimple();
 401
 402     /**
 403         Constructor creating the window.
 404
 405         Please see the base class wxHeaderCtrl::Create() method for the
 406         parameters description.
 407      */
 408     wxHeaderCtrlSimple(wxWindow *parent,
 409                        wxWindowID winid = wxID_ANY,
 410                        const wxPoint& pos = wxDefaultPosition,
 411                        const wxSize& size = wxDefaultSize,
 412                        long style = wxHD_DEFAULT_STYLE,
 413                        const wxString& name = wxHeaderCtrlNameStr);
 414
 415     /**
 416         Insert the column at the given position.
 417
 418         @param col
 419             The column to insert. Notice that because of the existence of
 420             implicit conversion from wxString to wxHeaderColumn a string
 421             can be passed directly here.
 422         @param idx
 423             The position of the new column, from 0 to GetColumnCount(). Using
 424             GetColumnCount() means to append the column to the end.
 425
 426         @see AppendColumn()
 427      */
 428     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 429
 430     /**
 431         Append the column to the end of the control.
 432
 433         @see InsertColumn()
 434      */
 435     void AppendColumn(const wxHeaderColumn& col);
 436
 437     /**
 438         Delete the column at the given position.
 439
 440         @see InsertColumn(), AppendColumn()
 441      */
 442     void DeleteColumn(unsigned int idx);
 443
 444     /**
 445         Show or hide the column.
 446
 447         Initially the column is shown by default or hidden if it was added with
 448         wxCOL_HIDDEN flag set.
 449
 450         When a column is hidden, it doesn't appear at all on the screen but its
 451         index is still taken into account when working with other columns. E.g.
 452         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 453         still need to use index 2 to refer to the last visible column.
 454
 455         @param idx
 456             The index of the column to show or hide, from 0 to GetColumnCount().
 457         @param show
 458             Indicates whether the column should be shown (default) or hidden.
 459      */
 460     void ShowColumn(unsigned int idx, bool show = true);
 461
 462     /**
 463         Hide the column with the given index.
 464
 465         This is the same as calling @code ShowColumn(idx, false) @endcode.
 466
 467         @param idx
 468             The index of the column to show or hide, from 0 to GetColumnCount().
 469      */
 470     void HideColumn(unsigned int idx);
 471
 472     /**
 473         Update the column sort indicator.
 474
 475         The sort indicator, if shown, is typically an arrow pointing upwards or
 476         downwards depending on whether the control contents is sorted in
 477         ascending or descending order.
 478
 479         @param idx
 480             The column to set the sort indicator for.
 481         @param sortOrder
 482             If @true or @false show the sort indicator corresponding to
 483             ascending or descending sort order respectively, if @c -1 remove
 484             the currently shown sort indicator.
 485      */
 486     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 487
 488     /**
 489         Remove the sort indicator from the given column.
 490
 491         This is the same as calling ShowSortIndicator() with @c -1 argument.
 492
 493         @param idx
 494             The column to remove sort indicator for.
 495      */
 496     void RemoveSortIndicator(unsigned int idx);
 497
 498 protected:
 499     /**
 500         This function can be overridden in the classes deriving from this
 501         control instead of overriding UpdateColumnWidthToFit().
 502
 503         To implement automatic column resizing to fit its contents width when
 504         the column divider is double clicked, you need to simply return the
 505         fitting width for the given column @a idx from this method, the control
 506         will automatically use the biggest value between the one returned from
 507         here and the one needed for the display of the column title itself.
 508
 509         The base class version returns -1 indicating that this function is not
 510         implemented.
 511      */
 512     virtual int GetBestFittingWidth(unsigned int idx) const;
 513 };
 514
 515 /**
 516     @class wxHeaderCtrlEvent
 517
 518     Event class representing the events generated by wxHeaderCtrl.
 519
 520     @library{wxcore}
 521     @category{ctrl}
 522
 523     @see wxHeaderCtrl
 524 */
 525 class wxHeaderCtrlEvent : public wxNotifyEvent
 526 {
 527 public:
 528     /**
 529         Return the index of the column affected by this event.
 530
 531         This method can be called for all header control events.
 532      */
 533     int GetColumn() const;
 534
 535     /**
 536         Return the current width of the column.
 537
 538         This method can only be called for the dragging events.
 539      */
 540     int GetWidth() const;
 541
 542     /**
 543         Return the new order of the column.
 544
 545         This method can only be called for end reorder event for which it
 546         indicates the tentative new position for the column GetColumn()
 547         selected by the user. If the event is not vetoed, this will become the
 548         new column position in wxHeaderCtrl::GetColumnsOrder().
 549      */
 550     unsigned int GetNewOrder() const;
 551 };