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_ALLOW_REORDER}
  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_ALLOW_REORDER.
  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_ALLOW_REORDER 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_ALLOW_REORDER @endcode if
 165             this is 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_ALLOW_REORDER style the returned array
 240         will be the same as was passed to SetColumnsOrder() previously or
 241         define the default order (with n-th element being n) if it hadn't been
 242         called. But for the controls with wxHD_ALLOW_REORDER style, the columns
 243         can be also 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         Reset the columns order to the natural one.
 273
 274         After calling this function, the column with index @c idx appears at
 275         position @c idx in the control.
 276      */
 277     void ResetColumnsOrder();
 278
 279     /**
 280         Helper function to manipulate the array of column indices.
 281
 282         This function reshuffles the array of column indices indexed by
 283         positions (i.e. using the same convention as for SetColumnsOrder()) so
 284         that the column with the given index is found at the specified
 285         position.
 286
 287         @param order
 288             Array containing the indices of columns in order of their
 289             positions.
 290         @param idx
 291             The index of the column to move.
 292         @param pos
 293             The new position for the column @a idx.
 294      */
 295     static void MoveColumnInOrderArray(wxArrayInt& order,
 296                                        unsigned int idx,
 297                                        unsigned int pos);
 298
 299     /**
 300         Show the popup menu allowing the user to show or hide the columns.
 301
 302         This functions shows the popup menu containing all columns with check
 303         marks for the ones which are currently shown at the current mouse
 304         position. It is meant to be called from EVT_HEADER_RIGHT_CLICK handler
 305         and should toggle the visibility of the n-th column if the function
 306         returns valid column index and not wxID_NONE which is returned if the
 307         user cancels the menu.
 308
 309         @param title
 310             The title for the menu if not empty.
 311         @return
 312             A valid column index or wxID_NONE if the user didn't select any
 313             column.
 314      */
 315     int ShowColumnsMenu(const wxString& title = wxString());
 316
 317 protected:
 318     /**
 319         Method to be implemented by the derived classes to return the
 320         information for the given column.
 321
 322         @param idx
 323             The column index, between 0 and the value last passed to
 324             SetColumnCount().
 325      */
 326     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 327
 328     /**
 329         Method which may be implemented by the derived classes to allow double
 330         clicking the column separator to resize the column to fit its contents.
 331
 332         When a separator is double clicked, the default handler of
 333         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 334         column if it returns @true so to implement the resizing of the column
 335         to fit its width on header double click you need to implement this
 336         method using logic similar to this example:
 337         @code
 338             class MyHeaderCtrl : public wxHeaderColumnBase
 339             {
 340             public:
 341                 ...
 342
 343                 void SetWidth(int width) { m_width = width; }
 344                 virtual int GetWidth() const { return m_width; }
 345
 346             private:
 347                 int m_width;
 348             };
 349
 350             class MyHeaderCtrl : public wxHeaderCtrl
 351             {
 352             public:
 353             protected:
 354                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 355                 {
 356                     return m_cols[idx];
 357                 }
 358
 359                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 360                 {
 361                     int widthContents = ... compute minimal width for column idx ...
 362                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 363                     return true;
 364                 }
 365
 366                 wxVector<MyHeaderColumn> m_cols;
 367             };
 368         @endcode
 369
 370         Base class version simply returns @false.
 371
 372         @param idx
 373             The zero-based index of the column to update.
 374         @param widthTitle
 375             Contains minimal width needed to display the column header itself
 376             and will usually be used as a starting point for the fitting width
 377             calculation.
 378
 379         @return
 380             @true to indicate that the column was resized, i.e. GetColumn() now
 381             returns the new width value, and so must be refreshed or @false
 382             meaning that the control didn't reach to the separator double click.
 383      */
 384     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 385
 386     /**
 387         Can be overridden in the derived class to update internal data
 388         structures when the number of the columns in the control changes.
 389
 390         This method is called by SetColumnCount() before effectively changing
 391         the number of columns.
 392
 393         The base class version does nothing but it is good practice to still
 394         call it from the overridden version in the derived class.
 395      */
 396     virtual void OnColumnCountChanging(unsigned int count);
 397 };
 398
 399
 400 /**
 401     @class wxHeaderCtrlSimple
 402
 403     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 404     without inheriting from it as you need to do when using wxHeaderCtrl
 405     itself.
 406
 407     When using it, you need to use simple AppendColumn(), InsertColumn() and
 408     DeleteColumn() methods instead of setting the number of columns with
 409     SetColumnCount() and returning the information about them from the
 410     overridden GetColumn().
 411
 412     @library{wxcore}
 413     @category{ctrl}
 414
 415     @see wxHeaderCtrl
 416 */
 417 class wxHeaderCtrlSimple : public wxHeaderCtrl
 418 {
 419 public:
 420     /**
 421         Default constructor not creating the underlying window.
 422
 423         You must use Create() after creating the object using this constructor.
 424      */
 425     wxHeaderCtrlSimple();
 426
 427     /**
 428         Constructor creating the window.
 429
 430         Please see the base class wxHeaderCtrl::Create() method for the
 431         parameters description.
 432      */
 433     wxHeaderCtrlSimple(wxWindow *parent,
 434                        wxWindowID winid = wxID_ANY,
 435                        const wxPoint& pos = wxDefaultPosition,
 436                        const wxSize& size = wxDefaultSize,
 437                        long style = wxHD_DEFAULT_STYLE,
 438                        const wxString& name = wxHeaderCtrlNameStr);
 439
 440     /**
 441         Insert the column at the given position.
 442
 443         @param col
 444             The column to insert. Notice that because of the existence of
 445             implicit conversion from wxString to wxHeaderColumn a string
 446             can be passed directly here.
 447         @param idx
 448             The position of the new column, from 0 to GetColumnCount(). Using
 449             GetColumnCount() means to append the column to the end.
 450
 451         @see AppendColumn()
 452      */
 453     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 454
 455     /**
 456         Append the column to the end of the control.
 457
 458         @see InsertColumn()
 459      */
 460     void AppendColumn(const wxHeaderColumn& col);
 461
 462     /**
 463         Delete the column at the given position.
 464
 465         @see InsertColumn(), AppendColumn()
 466      */
 467     void DeleteColumn(unsigned int idx);
 468
 469     /**
 470         Show or hide the column.
 471
 472         Initially the column is shown by default or hidden if it was added with
 473         wxCOL_HIDDEN flag set.
 474
 475         When a column is hidden, it doesn't appear at all on the screen but its
 476         index is still taken into account when working with other columns. E.g.
 477         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 478         still need to use index 2 to refer to the last visible column.
 479
 480         @param idx
 481             The index of the column to show or hide, from 0 to GetColumnCount().
 482         @param show
 483             Indicates whether the column should be shown (default) or hidden.
 484      */
 485     void ShowColumn(unsigned int idx, bool show = true);
 486
 487     /**
 488         Hide the column with the given index.
 489
 490         This is the same as calling @code ShowColumn(idx, false) @endcode.
 491
 492         @param idx
 493             The index of the column to show or hide, from 0 to GetColumnCount().
 494      */
 495     void HideColumn(unsigned int idx);
 496
 497     /**
 498         Update the column sort indicator.
 499
 500         The sort indicator, if shown, is typically an arrow pointing upwards or
 501         downwards depending on whether the control contents is sorted in
 502         ascending or descending order.
 503
 504         @param idx
 505             The column to set the sort indicator for.
 506         @param sortOrder
 507             If @true or @false show the sort indicator corresponding to
 508             ascending or descending sort order respectively, if @c -1 remove
 509             the currently shown sort indicator.
 510      */
 511     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 512
 513     /**
 514         Remove the sort indicator from the given column.
 515
 516         This is the same as calling ShowSortIndicator() with @c -1 argument.
 517
 518         @param idx
 519             The column to remove sort indicator for.
 520      */
 521     void RemoveSortIndicator(unsigned int idx);
 522
 523 protected:
 524     /**
 525         This function can be overridden in the classes deriving from this
 526         control instead of overriding UpdateColumnWidthToFit().
 527
 528         To implement automatic column resizing to fit its contents width when
 529         the column divider is double clicked, you need to simply return the
 530         fitting width for the given column @a idx from this method, the control
 531         will automatically use the biggest value between the one returned from
 532         here and the one needed for the display of the column title itself.
 533
 534         The base class version returns -1 indicating that this function is not
 535         implemented.
 536      */
 537     virtual int GetBestFittingWidth(unsigned int idx) const;
 538 };
 539
 540 /**
 541     @class wxHeaderCtrlEvent
 542
 543     Event class representing the events generated by wxHeaderCtrl.
 544
 545     @library{wxcore}
 546     @category{ctrl}
 547
 548     @see wxHeaderCtrl
 549 */
 550 class wxHeaderCtrlEvent : public wxNotifyEvent
 551 {
 552 public:
 553     /**
 554         Return the index of the column affected by this event.
 555
 556         This method can be called for all header control events.
 557      */
 558     int GetColumn() const;
 559
 560     /**
 561         Return the current width of the column.
 562
 563         This method can only be called for the dragging events.
 564      */
 565     int GetWidth() const;
 566
 567     /**
 568         Return the new order of the column.
 569
 570         This method can only be called for end reorder event for which it
 571         indicates the tentative new position for the column GetColumn()
 572         selected by the user. If the event is not vetoed, this will become the
 573         new column position in wxHeaderCtrl::GetColumnsOrder().
 574      */
 575     unsigned int GetNewOrder() const;
 576 };