interface/wx/headerctrl.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/headerctrl.h
   3 // Purpose:     interface of wxHeaderCtrl
   4 // Author:      Vadim Zeitlin
   5 // Created:     2008-12-01
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2008 Vadim Zeitlin <vadim@wxwidgets.org>
   8 // Licence:     wxWindows license
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 /**
  12     @class wxHeaderCtrl
  13
  14     wxHeaderCtrl is the control containing the column headings which is usually
  15     used for display of tabular data.
  16
  17     It is used as part of wxGrid and (will be used in the near future) in
  18     in wxDataViewCtrl and report view of wxListCtrl but can be also used
  19     independently. In general this class is meant to be used as part of another
  20     control which already stores the column information somewhere as it can't
  21     be used directly: instead you need to inherit from it and implement the
  22     GetColumn() method to provide column information. See wxHeaderCtrlSimple
  23     for a concrete control class which can be used directly.
  24
  25     In addition to labeling the columns, the control has the following
  26     features:
  27         - Column reordering support, either by explicitly configuring the
  28           columns order and calling SetColumnsOrder() or by dragging the
  29           columns interactively (if enabled).
  30         - Display of the icons in the header: this is often used to display a
  31           sort or reverse sort indicator when the column header is clicked.
  32
  33     Notice that this control itself doesn't do anything other than displaying
  34     the column headers. In particular column reordering and sorting must still
  35     be supported by the associated control displaying the real data under the
  36     header. Also remember to call ScrollWindow() method of the control if the
  37     associated data display window has a horizontal scrollbar, otherwise the
  38     headers wouldn't align with the data when the window is scrolled.
  39
  40     This control is implemented using the native header control under MSW
  41     systems and a generic implementation elsewhere.
  42
  43     @beginStyleTable
  44         @style{wxHD_DRAGDROP}
  45             If this style is specified (it is by default), the user can reorder
  46             the control columns by dragging them.
  47         @style{wxHD_DEFAULT_STYLE}
  48             Symbolic name for the default control style, currently equal to @c
  49             wxHD_DRAGDROP.
  50     @endStyleTable
  51
  52     @beginEventTable{wxHeaderCtrlEvent}
  53         @event{EVT_HEADER_CLICK(id, func)}
  54             A column heading was clicked.
  55         @event{EVT_HEADER_RIGHT_CLICK(id, func)}
  56             A column heading was right clicked.
  57         @event{EVT_HEADER_MIDDLE_CLICK(id, func)}
  58             A column heading was clicked with the middle mouse button.
  59
  60         @event{EVT_HEADER_DCLICK(id, func)}
  61             A column heading was double clicked.
  62         @event{EVT_HEADER_RIGHT_DCLICK(id, func)}
  63             A column heading was right double clicked.
  64         @event{EVT_HEADER_MIDDLE_DCLICK(id, func)}
  65             A column heading was double clicked with the middle mouse button.
  66
  67         @event{EVT_HEADER_SEPARATOR_DCLICK(id, func)}
  68             Separator to the right of the specified column was double clicked
  69             (this action is commonly used to resize the column to fit its
  70             contents width and the control provides UpdateColumnWidthToFit() method
  71             to make implementing this easier).
  72
  73         @event{EVT_HEADER_BEGIN_RESIZE(id, func)}
  74             The user started to drag the separator to the right of the column
  75             with the specified index (this can only happen for the columns for
  76             which wxHeaderColumn::IsResizeable() returns true). The event can
  77             be vetoed to prevent the column from being resized. If it isn't,
  78             the resizing and end resize events will be generated later.
  79         @event{EVT_HEADER_RESIZING(id, func)}
  80             The user is dragging the column with the specified index resizing
  81             it and its current width is wxHeaderCtrlEvent::GetWidth(). The
  82             event can be vetoed to stop the dragging operation completely at
  83             any time.
  84         @event{EVT_HEADER_END_RESIZE(id, func)}
  85             Either the user stopped dragging the column by releasing the mouse
  86             or the resizing was cancelled. If wxHeaderCtrlEvent::IsCancelled()
  87             returns @true, nothing should be done, otherwise the column should
  88             normally be resized to the value of wxHeaderCtrlEvent::GetWidth().
  89
  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             Either the user dropped the column in its new location or the
  97             drag operation was cancelled. If wxHeaderCtrlEvent::IsCancelled()
  98             returns @true, nothing should be done, otherwise the event can be
  99             vetoed to prevent the column from being placed at the new position
 100             or handled to update the display of the data in the associated
 101             control to match the new column location (available from
 102             wxHeaderCtrlEvent::GetNewOrder()).
 103     @endEventTable
 104
 105     @library{wxcore}
 106     @category{ctrl}
 107
 108     @see wxGrid, wxListCtrl, wxDataViewCtrl
 109
 110
 111     @section headerctrl_improvements Future Improvements
 112
 113     Some features are supported by the native MSW control and so could be
 114     easily implemented in this version of wxHeaderCtrl but need to be
 115     implemented in the generic version as well to be really useful. Please let
 116     us know if you need or, better, plan to work on implementing, any of them:
 117         - Displaying bitmaps instead of or together with the text
 118         - Custom drawn headers
 119         - Filters associated with a column.
 120 */
 121 class wxHeaderCtrl
 122 {
 123 public:
 124     /**
 125         Default constructor not creating the underlying window.
 126
 127         You must use Create() after creating the object using this constructor.
 128      */
 129     wxHeaderCtrl();
 130
 131     /**
 132         Constructor creating the window.
 133
 134         Please see Create() for the parameters documentation.
 135      */
 136     wxHeaderCtrl(wxWindow *parent,
 137                  wxWindowID winid = wxID_ANY,
 138                  const wxPoint& pos = wxDefaultPosition,
 139                  const wxSize& size = wxDefaultSize,
 140                  long style = wxHD_DEFAULT_STYLE,
 141                  const wxString& name = wxHeaderCtrlNameStr);
 142
 143     /**
 144         Create the header control window.
 145
 146         @param parent
 147             The parent window. The header control should be typically
 148             positioned along the top edge of this window.
 149         @param winid
 150             Id of the control or @c wxID_ANY if you don't care.
 151         @param pos
 152             The initial position of the control.
 153         @param size
 154             The initial size of the control (usually not very useful as this
 155             control will typically be resized to have the same width as the
 156             associated data display control).
 157         @param style
 158             The control style, @c wxHD_DEFAULT_STYLE by default. Notice that
 159             the default style allows the user to reorder the columns by
 160             dragging them and you need to explicitly turn this feature off by
 161             using @code wxHD_DEFAULT_STYLE & ~wxHD_DRAGDROP @endcode if this is
 162             undesirable.
 163         @param name
 164             The name of the control.
 165      */
 166     bool Create(wxWindow *parent,
 167                 wxWindowID winid = wxID_ANY,
 168                 const wxPoint& pos = wxDefaultPosition,
 169                 const wxSize& size = wxDefaultSize,
 170                 long style = wxHD_DEFAULT_STYLE,
 171                 const wxString& name = wxHeaderCtrlNameStr);
 172
 173     /**
 174         Set the number of columns in the control.
 175
 176         The control will use GetColumn() to get information about all the
 177         new columns and refresh itself, i.e. this method also has the same
 178         effect as calling UpdateColumn() for all columns but it should only be
 179         used if the number of columns really changed.
 180      */
 181     void SetColumnCount(unsigned int count);
 182
 183     /**
 184         Return the number of columns in the control.
 185
 186         @return
 187             Number of columns as previously set by SetColumnCount().
 188
 189         @see IsEmpty()
 190      */
 191     unsigned int GetColumnCount() const;
 192
 193     /**
 194         Return whether the control has any columns.
 195
 196         @see GetColumnCount()
 197      */
 198     bool IsEmpty() const;
 199
 200     /**
 201         Update the column with the given index.
 202
 203         When the value returned by GetColumn() changes, this method must be
 204         called to notify the control about the change and update the visual
 205         display to match the new column data.
 206
 207         @param idx
 208             The column index, must be less than GetColumnCount().
 209      */
 210     void UpdateColumn(unsigned int idx);
 211
 212     /**
 213         Change the columns display order.
 214
 215         The display order defines the order in which the columns appear on the
 216         screen and does @em not affect the interpretation of indices by all the
 217         other class methods.
 218
 219         The @a order array specifies the column indices corresponding to the
 220         display positions.
 221
 222         @param order
 223             A permutation of all column indices, i.e. an array of size
 224             GetColumnsOrder() containing all column indices exactly once. The
 225             n-th element of this array defines the index of the column shown at
 226             the n-th position from left (for the default left-to-right writing
 227             direction).
 228
 229         @see wxListCtrl::SetColumnsOrder()
 230      */
 231     void SetColumnsOrder(const wxArrayInt& order);
 232
 233     /**
 234         Return the array describing the columns display order.
 235
 236         For the controls without wxHD_DRAGDROP style the returned array will be
 237         the same as was passed to SetColumnsOrder() previously or define the
 238         default order (with n-th element being n) if it hadn't been called. But
 239         for the controls with wxHD_DRAGDROP style, the columns can be also
 240         reordered by user.
 241      */
 242     wxArrayInt GetColumnsOrder() const;
 243
 244     /**
 245         Return the index of the column displayed at the given position.
 246
 247         @param pos
 248             The display position, e.g. 0 for the left-most column, 1 for the
 249             next one and so on until GetColumnCount() - 1.
 250
 251         @see GetColumnPos()
 252      */
 253     unsigned int GetColumnAt(unsigned int pos) const;
 254
 255     /**
 256         Get the position at which this column is currently displayed.
 257
 258         Notice that a valid position is returned even for the hidden columns
 259         currently.
 260
 261         @param idx
 262             The column index, must be less than GetColumnCount().
 263
 264         @see GetColumnAt()
 265      */
 266     unsigned int GetColumnPos(unsigned int idx) const;
 267
 268 protected:
 269     /**
 270         Method to be implemented by the derived classes to return the
 271         information for the given column.
 272
 273         @param idx
 274             The column index, between 0 and the value last passed to
 275             SetColumnCount().
 276      */
 277     virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
 278
 279     /**
 280         Method which may be implemented by the derived classes to allow double
 281         clicking the column separator to resize the column to fit its contents.
 282
 283         When a separator is double clicked, the default handler of
 284         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 285         column if it returns @true so to implement the resizing of the column
 286         to fit its width on header double click you need to implement this
 287         method using logic similar to this example:
 288         @code
 289             class MyHeaderCtrl : public wxHeaderColumnBase
 290             {
 291             public:
 292                 ...
 293
 294                 void SetWidth(int width) { m_width = width; }
 295                 virtual int GetWidth() const { return m_width; }
 296
 297             private:
 298                 int m_width;
 299             };
 300
 301             class MyHeaderCtrl : public wxHeaderCtrl
 302             {
 303             public:
 304             protected:
 305                 virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
 306                 {
 307                     return m_cols[idx];
 308                 }
 309
 310                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 311                 {
 312                     int widthContents = ... compute minimal width for column idx ...
 313                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 314                     return true;
 315                 }
 316
 317                 wxVector<MyHeaderColumn> m_cols;
 318             };
 319         @endcode
 320
 321         Base class version simply returns @false.
 322
 323         @param width
 324             Contains minimal width needed to display the column header itself
 325             and will usually be used as a starting point for the fitting width
 326             calculation.
 327         @return
 328             @true to indicate that the column was resized, i.e. GetColumn() now
 329             returns the new width value, and so must be refreshed or @false
 330             meaning that the control didn't reach to the separator double click.
 331      */
 332     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 333 };
 334
 335
 336 /**
 337     @class wxHeaderCtrlSimple
 338
 339     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 340     without inheriting from it as you need to do when using wxHeaderCtrl
 341     itself.
 342
 343     When using it, you need to use simple AppendColumn(), InsertColumn() and
 344     DeleteColumn() methods instead of setting the number of columns with
 345     SetColumnCount() and returning the information about them from the
 346     overridden GetColumn().
 347
 348     @library{wxcore}
 349     @category{ctrl}
 350
 351     @see wxHeaderCtrl
 352 */
 353 class wxHeaderCtrlSimple : public wxHeaderCtrl
 354 {
 355 public:
 356     /**
 357         Default constructor not creating the underlying window.
 358
 359         You must use Create() after creating the object using this constructor.
 360      */
 361     wxHeaderCtrlSimple();
 362
 363     /**
 364         Constructor creating the window.
 365
 366         Please see the base class wxHeaderCtrl::Create() method for the
 367         parameters description.
 368      */
 369     wxHeaderCtrlSimple(wxWindow *parent,
 370                        wxWindowID winid = wxID_ANY,
 371                        const wxPoint& pos = wxDefaultPosition,
 372                        const wxSize& size = wxDefaultSize,
 373                        long style = wxHD_DEFAULT_STYLE,
 374                        const wxString& name = wxHeaderCtrlNameStr);
 375
 376     /**
 377         Insert the column at the given position.
 378
 379         @param col
 380             The column to insert. Notice that because of the existence of
 381             implicit conversion from wxString to wxHeaderColumn a string
 382             can be passed directly here.
 383         @param idx
 384             The position of the new column, from 0 to GetColumnCount(). Using
 385             GetColumnCount() means to append the column to the end.
 386
 387         @see AppendColumn()
 388      */
 389     void InsertColumn(const wxHeaderColumn& col, unsigned int idx);
 390
 391     /**
 392         Append the column to the end of the control.
 393
 394         @see InsertColumn()
 395      */
 396     void AppendColumn(const wxHeaderColumn& col);
 397
 398     /**
 399         Delete the column at the given position.
 400
 401         @see InsertColumn(), AppendColumn()
 402      */
 403     void DeleteColumn(unsigned int idx);
 404
 405     /**
 406         Show or hide the column.
 407
 408         Initially the column is shown by default or hidden if it was added with
 409         wxCOL_HIDDEN flag set.
 410
 411         When a column is hidden, it doesn't appear at all on the screen but its
 412         index is still taken into account when working with other columns. E.g.
 413         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 414         still need to use index 2 to refer to the last visible column.
 415
 416         @param idx
 417             The index of the column to show or hide, from 0 to GetColumnCount().
 418         @param show
 419             Indicates whether the column should be shown (default) or hidden.
 420      */
 421     void ShowColumn(unsigned int idx, bool show = true);
 422
 423     /**
 424         Hide the column with the given index.
 425
 426         This is the same as calling @code ShowColumn(idx, false) @endcode.
 427
 428         @param idx
 429             The index of the column to show or hide, from 0 to GetColumnCount().
 430      */
 431     void HideColumn(unsigned int idx);
 432
 433     /**
 434         Update the column sort indicator.
 435
 436         The sort indicator, if shown, is typically an arrow pointing upwards or
 437         downwards depending on whether the control contents is sorted in
 438         ascending or descending order.
 439
 440         @param idx
 441             The column to set the sort indicator for.
 442         @param sortOrder
 443             If @true or @false show the sort indicator corresponding to
 444             ascending or descending sort order respectively, if @c -1 remove
 445             the currently shown sort indicator.
 446      */
 447     virtual void ShowSortIndicator(unsigned int idx, int sortOrder);
 448
 449     /**
 450         Remove the sort indicator from the given column.
 451
 452         This is the same as calling ShowSortIndicator() with @c -1 argument.
 453
 454         @param idx
 455             The column to remove sort indicator for.
 456      */
 457     void RemoveSortIndicator(unsigned int idx);
 458
 459 protected:
 460     /**
 461         This function can be overridden in the classes deriving from this
 462         control instead of overriding UpdateColumnWidthToFit().
 463
 464         To implement automatic column resizing to fit its contents width when
 465         the column divider is double clicked, you need to simply return the
 466         fitting width for the given column @a idx from this method, the control
 467         will automatically use the biggest value between the one returned from
 468         here and the one needed for the display of the column title itself.
 469
 470         The base class version returns -1 indicating that this function is not
 471         implemented.
 472      */
 473     virtual int GetBestFittingWidth(unsigned int idx) const;
 474 };
 475
 476 /**
 477     @class wxHeaderCtrlEvent
 478
 479     Event class representing the events generated by wxHeaderCtrl.
 480
 481     @library{wxcore}
 482     @category{ctrl}
 483
 484     @see wxHeaderCtrl
 485 */
 486 class wxHeaderCtrlEvent : public wxNotifyEvent
 487 {
 488 public:
 489     /**
 490         Return the index of the column affected by this event.
 491
 492         This method can be called for all header control events.
 493      */
 494     int GetColumn() const;
 495
 496     /**
 497         Return the current width of the column.
 498
 499         This method can only be called for the dragging events.
 500      */
 501     int GetWidth() const;
 502
 503     /**
 504         Return the new order of the column.
 505
 506         This method can only be called for end reorder event for which it
 507         indicates the tentative new position for the column GetColumn()
 508         selected by the user. If the event is not vetoed, this will become the
 509         new column position in wxHeaderCtrl::GetColumnsOrder().
 510      */
 511     unsigned int GetNewOrder() const;
 512
 513     /**
 514         Return @true if the drag operation was cancelled.
 515
 516         This method can only be called for the end drag event.
 517      */
 518     bool IsCancelled() const;
 519 };