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