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
  44     @section headerctrl_improvements Future Improvements
  45
  46     Some features are supported by the native MSW control and so could be
  47     easily implemented in this version of wxHeaderCtrl but need to be
  48     implemented in the generic version as well to be really useful. Please let
  49     us know if you need or, better, plan to work on implementing, any of them:
  50         - Displaying bitmaps instead of or together with the text
  51         - Custom drawn headers
  52         - Filters associated with a column.
  53
  54
  55     @beginStyleTable
  56     @style{wxHD_DRAGDROP}
  57         If this style is specified (it is by default), the user can reorder
  58         the control columns by dragging them.
  59     @style{wxHD_DEFAULT_STYLE}
  60         Symbolic name for the default control style, currently equal to
  61         @c wxHD_DRAGDROP.
  62     @endStyleTable
  63
  64     @beginEventTable{wxHeaderCtrlEvent}
  65     @event{EVT_HEADER_CLICK(id, func)}
  66         A column heading was clicked.
  67     @event{EVT_HEADER_RIGHT_CLICK(id, func)}
  68         A column heading was right clicked.
  69     @event{EVT_HEADER_MIDDLE_CLICK(id, func)}
  70         A column heading was clicked with the middle mouse button.
  71     @event{EVT_HEADER_DCLICK(id, func)}
  72         A column heading was double clicked.
  73     @event{EVT_HEADER_RIGHT_DCLICK(id, func)}
  74         A column heading was right double clicked.
  75     @event{EVT_HEADER_MIDDLE_DCLICK(id, func)}
  76         A column heading was double clicked with the middle mouse button.
  77     @event{EVT_HEADER_SEPARATOR_DCLICK(id, func)}
  78         Separator to the right of the specified column was double clicked
  79         (this action is commonly used to resize the column to fit its
  80         contents width and the control provides UpdateColumnWidthToFit() method
  81         to make implementing this easier).
  82     @event{EVT_HEADER_BEGIN_RESIZE(id, func)}
  83         The user started to drag the separator to the right of the column
  84         with the specified index (this can only happen for the columns for
  85         which wxHeaderColumn::IsResizeable() returns true). The event can
  86         be vetoed to prevent the column from being resized. If it isn't,
  87         the resizing and end resize (or dragging cancelled) events will be
  88         generated later.
  89     @event{EVT_HEADER_RESIZING(id, func)}
  90         The user is dragging the column with the specified index resizing
  91         it and its current width is wxHeaderCtrlEvent::GetWidth().
  92         The event can be vetoed to stop the dragging operation completely at
  93         any time.
  94     @event{EVT_HEADER_END_RESIZE(id, func)}
  95         The user stopped dragging the column by releasing the mouse.
  96         The column should normally be resized to the value of
  97         wxHeaderCtrlEvent::GetWidth().
  98     @event{EVT_HEADER_BEGIN_REORDER(id, func)}
  99         The user started to drag the column with the specified index (this
 100         can only happen for the controls with wxHD_DRAGDROP style).
 101         This event can be vetoed to prevent the column from being reordered,
 102         otherwise the end reorder message will be generated later.
 103     @event{EVT_HEADER_END_REORDER(id, func)}
 104         The user dropped the column in its new location. The event can be
 105         vetoed to prevent the column from being placed at the new position
 106         or handled to update the display of the data in the associated
 107         control to match the new column location (available from
 108         wxHeaderCtrlEvent::GetNewOrder()).
 109     @event{EVT_HEADER_DRAGGING_CANCELLED(id, func)}
 110         The resizing or reordering operation currently in progress was
 111         cancelled. This can happen if the user pressed Esc key while
 112         dragging the mouse or the mouse capture was lost for some other
 113         reason. You only need to handle this event if your application
 114         entered into some modal mode when resizing or reordering began, in
 115         which case it should handle this event in addition to the matching
 116         end resizing or reordering ones.
 117     @endEventTable
 118
 119     @library{wxcore}
 120     @category{ctrl}
 121
 122     @see wxGrid, wxListCtrl, wxDataViewCtrl
 123 */
 124 class wxHeaderCtrl
 125 {
 126 public:
 127     /**
 128         Default constructor not creating the underlying window.
 129
 130         You must use Create() after creating the object using this constructor.
 131      */
 132     wxHeaderCtrl();
 133
 134     /**
 135         Constructor creating the window.
 136
 137         Please see Create() for the parameters documentation.
 138      */
 139     wxHeaderCtrl(wxWindow *parent,
 140                  wxWindowID winid = wxID_ANY,
 141                  const wxPoint& pos = wxDefaultPosition,
 142                  const wxSize& size = wxDefaultSize,
 143                  long style = wxHD_DEFAULT_STYLE,
 144                  const wxString& name = wxHeaderCtrlNameStr);
 145
 146     /**
 147         Create the header control window.
 148
 149         @param parent
 150             The parent window. The header control should be typically
 151             positioned along the top edge of this window.
 152         @param winid
 153             Id of the control or @c wxID_ANY if you don't care.
 154         @param pos
 155             The initial position of the control.
 156         @param size
 157             The initial size of the control (usually not very useful as this
 158             control will typically be resized to have the same width as the
 159             associated data display control).
 160         @param style
 161             The control style, @c wxHD_DEFAULT_STYLE by default. Notice that
 162             the default style allows the user to reorder the columns by
 163             dragging them and you need to explicitly turn this feature off by
 164             using @code wxHD_DEFAULT_STYLE & ~wxHD_DRAGDROP @endcode if this is
 165             undesirable.
 166         @param name
 167             The name of the control.
 168      */
 169     bool Create(wxWindow *parent,
 170                 wxWindowID winid = wxID_ANY,
 171                 const wxPoint& pos = wxDefaultPosition,
 172                 const wxSize& size = wxDefaultSize,
 173                 long style = wxHD_DEFAULT_STYLE,
 174                 const wxString& name = wxHeaderCtrlNameStr);
 175
 176     /**
 177         Set the number of columns in the control.
 178
 179         The control will use GetColumn() to get information about all the
 180         new columns and refresh itself, i.e. this method also has the same
 181         effect as calling UpdateColumn() for all columns but it should only be
 182         used if the number of columns really changed.
 183      */
 184     void SetColumnCount(unsigned int count);
 185
 186     /**
 187         Return the number of columns in the control.
 188
 189         @return
 190             Number of columns as previously set by SetColumnCount().
 191
 192         @see IsEmpty()
 193      */
 194     unsigned int GetColumnCount() const;
 195
 196     /**
 197         Return whether the control has any columns.
 198
 199         @see GetColumnCount()
 200      */
 201     bool IsEmpty() const;
 202
 203     /**
 204         Update the column with the given index.
 205
 206         When the value returned by GetColumn() changes, this method must be
 207         called to notify the control about the change and update the visual
 208         display to match the new column data.
 209
 210         @param idx
 211             The column index, must be less than GetColumnCount().
 212      */
 213     void UpdateColumn(unsigned int idx);
 214
 215     /**
 216         Change the columns display order.
 217
 218         The display order defines the order in which the columns appear on the
 219         screen and does @em not affect the interpretation of indices by all the
 220         other class methods.
 221
 222         The @a order array specifies the column indices corresponding to the
 223         display positions.
 224
 225         @param order
 226             A permutation of all column indices, i.e. an array of size
 227             GetColumnsOrder() containing all column indices exactly once. The
 228             n-th element of this array defines the index of the column shown at
 229             the n-th position from left (for the default left-to-right writing
 230             direction).
 231
 232         @see wxListCtrl::SetColumnsOrder()
 233      */
 234     void SetColumnsOrder(const wxArrayInt& order);
 235
 236     /**
 237         Return the array describing the columns display order.
 238
 239         For the controls without wxHD_DRAGDROP style the returned array will be
 240         the same as was passed to SetColumnsOrder() previously or define the
 241         default order (with n-th element being n) if it hadn't been called. But
 242         for the controls with wxHD_DRAGDROP style, the columns can be also
 243         reordered by user.
 244      */
 245     wxArrayInt GetColumnsOrder() const;
 246
 247     /**
 248         Return the index of the column displayed at the given position.
 249
 250         @param pos
 251             The display position, e.g. 0 for the left-most column, 1 for the
 252             next one and so on until GetColumnCount() - 1.
 253
 254         @see GetColumnPos()
 255      */
 256     unsigned int GetColumnAt(unsigned int pos) const;
 257
 258     /**
 259         Get the position at which this column is currently displayed.
 260
 261         Notice that a valid position is returned even for the hidden columns
 262         currently.
 263
 264         @param idx
 265             The column index, must be less than GetColumnCount().
 266
 267         @see GetColumnAt()
 268      */
 269     unsigned int GetColumnPos(unsigned int idx) const;
 270
 271     /**
 272         Helper function to manipulate the array of column indices.
 273
 274         This function reshuffles the array of column indices indexed by
 275         positions (i.e. using the same convention as for SetColumnsOrder()) so
 276         that the column with the given index is found at the specified
 277         position.
 278
 279         @param order
 280             Array containing the indices of columns in order of their
 281             positions.
 282         @param idx
 283             The index of the column to move.
 284         @param pos
 285             The new position for the column @a idx.
 286      */
 287     static void MoveColumnInOrderArray(wxArrayInt& order,
 288                                        unsigned int idx,
 289                                        unsigned int pos);
 290
 291 protected:
 292     /**
 293         Method to be implemented by the derived classes to return the
 294         information for the given column.
 295
 296         @param idx
 297             The column index, between 0 and the value last passed to
 298             SetColumnCount().
 299      */
 300     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 301
 302     /**
 303         Method which may be implemented by the derived classes to allow double
 304         clicking the column separator to resize the column to fit its contents.
 305
 306         When a separator is double clicked, the default handler of
 307         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 308         column if it returns @true so to implement the resizing of the column
 309         to fit its width on header double click you need to implement this
 310         method using logic similar to this example:
 311         @code
 312             class MyHeaderCtrl : public wxHeaderColumnBase
 313             {
 314             public:
 315                 ...
 316
 317                 void SetWidth(int width) { m_width = width; }
 318                 virtual int GetWidth() const { return m_width; }
 319
 320             private:
 321                 int m_width;
 322             };
 323
 324             class MyHeaderCtrl : public wxHeaderCtrl
 325             {
 326             public:
 327             protected:
 328                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 329                 {
 330                     return m_cols[idx];
 331                 }
 332
 333                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 334                 {
 335                     int widthContents = ... compute minimal width for column idx ...
 336                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 337                     return true;
 338                 }
 339
 340                 wxVector<MyHeaderColumn> m_cols;
 341             };
 342         @endcode
 343
 344         Base class version simply returns @false.
 345
 346         @param idx
 347             The zero-based index of the column to update.
 348         @param widthTitle
 349             Contains minimal width needed to display the column header itself
 350             and will usually be used as a starting point for the fitting width
 351             calculation.
 352
 353         @return
 354             @true to indicate that the column was resized, i.e. GetColumn() now
 355             returns the new width value, and so must be refreshed or @false
 356             meaning that the control didn't reach to the separator double click.
 357      */
 358     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 359
 360     /**
 361         Can be overridden in the derived class to update internal data
 362         structures when the number of the columns in the control changes.
 363
 364         This method is called by SetColumnCount() before effectively changing
 365         the number of columns.
 366
 367         The base class version does nothing but it is good practice to still
 368         call it from the overridden version in the derived class.
 369      */
 370     virtual void OnColumnCountChanging(unsigned int count);
 371 };
 372
 373
 374 /**
 375     @class wxHeaderCtrlSimple
 376
 377     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 378     without inheriting from it as you need to do when using wxHeaderCtrl
 379     itself.
 380
 381     When using it, you need to use simple AppendColumn(), InsertColumn() and
 382     DeleteColumn() methods instead of setting the number of columns with
 383     SetColumnCount() and returning the information about them from the
 384     overridden GetColumn().
 385
 386     @library{wxcore}
 387     @category{ctrl}
 388
 389     @see wxHeaderCtrl
 390 */
 391 class wxHeaderCtrlSimple : public wxHeaderCtrl
 392 {
 393 public:
 394     /**
 395         Default constructor not creating the underlying window.
 396
 397         You must use Create() after creating the object using this constructor.
 398      */
 399     wxHeaderCtrlSimple();
 400
 401     /**
 402         Constructor creating the window.
 403
 404         Please see the base class wxHeaderCtrl::Create() method for the
 405         parameters description.
 406      */
 407     wxHeaderCtrlSimple(wxWindow *parent,
 408                        wxWindowID winid = wxID_ANY,
 409                        const wxPoint& pos = wxDefaultPosition,
 410                        const wxSize& size = wxDefaultSize,
 411                        long style = wxHD_DEFAULT_STYLE,
 412                        const wxString& name = wxHeaderCtrlNameStr);
 413
 414     /**
 415         Insert the column at the given position.
 416
 417         @param col
 418             The column to insert. Notice that because of the existence of
 419             implicit conversion from wxString to wxHeaderColumn a string
 420             can be passed directly here.
 421         @param idx
 422             The position of the new column, from 0 to GetColumnCount(). Using
 423             GetColumnCount() means to append the column to the end.
 424
 425         @see AppendColumn()
 426      */
 427     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 428
 429     /**
 430         Append the column to the end of the control.
 431
 432         @see InsertColumn()
 433      */
 434     void AppendColumn(const wxHeaderColumn& col);
 435
 436     /**
 437         Delete the column at the given position.
 438
 439         @see InsertColumn(), AppendColumn()
 440      */
 441     void DeleteColumn(unsigned int idx);
 442
 443     /**
 444         Show or hide the column.
 445
 446         Initially the column is shown by default or hidden if it was added with
 447         wxCOL_HIDDEN flag set.
 448
 449         When a column is hidden, it doesn't appear at all on the screen but its
 450         index is still taken into account when working with other columns. E.g.
 451         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 452         still need to use index 2 to refer to the last visible column.
 453
 454         @param idx
 455             The index of the column to show or hide, from 0 to GetColumnCount().
 456         @param show
 457             Indicates whether the column should be shown (default) or hidden.
 458      */
 459     void ShowColumn(unsigned int idx, bool show = true);
 460
 461     /**
 462         Hide the column with the given index.
 463
 464         This is the same as calling @code ShowColumn(idx, false) @endcode.
 465
 466         @param idx
 467             The index of the column to show or hide, from 0 to GetColumnCount().
 468      */
 469     void HideColumn(unsigned int idx);
 470
 471     /**
 472         Update the column sort indicator.
 473
 474         The sort indicator, if shown, is typically an arrow pointing upwards or
 475         downwards depending on whether the control contents is sorted in
 476         ascending or descending order.
 477
 478         @param idx
 479             The column to set the sort indicator for.
 480         @param sortOrder
 481             If @true or @false show the sort indicator corresponding to
 482             ascending or descending sort order respectively, if @c -1 remove
 483             the currently shown sort indicator.
 484      */
 485     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 486
 487     /**
 488         Remove the sort indicator from the given column.
 489
 490         This is the same as calling ShowSortIndicator() with @c -1 argument.
 491
 492         @param idx
 493             The column to remove sort indicator for.
 494      */
 495     void RemoveSortIndicator(unsigned int idx);
 496
 497 protected:
 498     /**
 499         This function can be overridden in the classes deriving from this
 500         control instead of overriding UpdateColumnWidthToFit().
 501
 502         To implement automatic column resizing to fit its contents width when
 503         the column divider is double clicked, you need to simply return the
 504         fitting width for the given column @a idx from this method, the control
 505         will automatically use the biggest value between the one returned from
 506         here and the one needed for the display of the column title itself.
 507
 508         The base class version returns -1 indicating that this function is not
 509         implemented.
 510      */
 511     virtual int GetBestFittingWidth(unsigned int idx) const;
 512 };
 513
 514 /**
 515     @class wxHeaderCtrlEvent
 516
 517     Event class representing the events generated by wxHeaderCtrl.
 518
 519     @library{wxcore}
 520     @category{ctrl}
 521
 522     @see wxHeaderCtrl
 523 */
 524 class wxHeaderCtrlEvent : public wxNotifyEvent
 525 {
 526 public:
 527     /**
 528         Return the index of the column affected by this event.
 529
 530         This method can be called for all header control events.
 531      */
 532     int GetColumn() const;
 533
 534     /**
 535         Return the current width of the column.
 536
 537         This method can only be called for the dragging events.
 538      */
 539     int GetWidth() const;
 540
 541     /**
 542         Return the new order of the column.
 543
 544         This method can only be called for end reorder event for which it
 545         indicates the tentative new position for the column GetColumn()
 546         selected by the user. If the event is not vetoed, this will become the
 547         new column position in wxHeaderCtrl::GetColumnsOrder().
 548      */
 549     unsigned int GetNewOrder() const;
 550 };