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, in generic version wxDataViewCtrl and report
  18     view of wxListCtrl but can be also used independently. In general this
  19     class is meant to be used as part of another control which already stores
  20     the column information somewhere as it can't be used directly: instead you
  21     need to inherit from it and implement the GetColumn() method to provide
  22     column information. See wxHeaderCtrlSimple for a concrete control class
  23     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_ALLOW_HIDE}
  60         If this style is specified, the control shows a popup menu allowing the
  61         user to change the columns visibility on right mouse click. Notice that
  62         the program can always hide or show the columns, this style only
  63         affects the users capability to do it.
  64     @style{wxHD_DEFAULT_STYLE}
  65         Symbolic name for the default control style, currently equal to
  66         @c wxHD_ALLOW_REORDER.
  67     @endStyleTable
  68
  69     @beginEventEmissionTable{wxHeaderCtrlEvent}
  70     @event{EVT_HEADER_CLICK(id, func)}
  71         A column heading was clicked.
  72     @event{EVT_HEADER_RIGHT_CLICK(id, func)}
  73         A column heading was right clicked.
  74     @event{EVT_HEADER_MIDDLE_CLICK(id, func)}
  75         A column heading was clicked with the middle mouse button.
  76     @event{EVT_HEADER_DCLICK(id, func)}
  77         A column heading was double clicked.
  78     @event{EVT_HEADER_RIGHT_DCLICK(id, func)}
  79         A column heading was right double clicked.
  80     @event{EVT_HEADER_MIDDLE_DCLICK(id, func)}
  81         A column heading was double clicked with the middle mouse button.
  82     @event{EVT_HEADER_SEPARATOR_DCLICK(id, func)}
  83         Separator to the right of the specified column was double clicked
  84         (this action is commonly used to resize the column to fit its
  85         contents width and the control provides UpdateColumnWidthToFit() method
  86         to make implementing this easier).
  87     @event{EVT_HEADER_BEGIN_RESIZE(id, func)}
  88         The user started to drag the separator to the right of the column
  89         with the specified index (this can only happen for the columns for
  90         which wxHeaderColumn::IsResizeable() returns true). The event can
  91         be vetoed to prevent the column from being resized. If it isn't,
  92         the resizing and end resize (or dragging cancelled) events will be
  93         generated later.
  94     @event{EVT_HEADER_RESIZING(id, func)}
  95         The user is dragging the column with the specified index resizing
  96         it and its current width is wxHeaderCtrlEvent::GetWidth().
  97         The event can be vetoed to stop the dragging operation completely at
  98         any time.
  99     @event{EVT_HEADER_END_RESIZE(id, func)}
 100         The user stopped dragging the column by releasing the mouse.
 101         The column should normally be resized to the value of
 102         wxHeaderCtrlEvent::GetWidth().
 103     @event{EVT_HEADER_BEGIN_REORDER(id, func)}
 104         The user started to drag the column with the specified index (this
 105         can only happen for the controls with wxHD_ALLOW_REORDER style).
 106         This event can be vetoed to prevent the column from being reordered,
 107         otherwise the end reorder message will be generated later.
 108     @event{EVT_HEADER_END_REORDER(id, func)}
 109         The user dropped the column in its new location. The event can be
 110         vetoed to prevent the column from being placed at the new position
 111         or handled to update the display of the data in the associated
 112         control to match the new column location (available from
 113         wxHeaderCtrlEvent::GetNewOrder()).
 114     @event{EVT_HEADER_DRAGGING_CANCELLED(id, func)}
 115         The resizing or reordering operation currently in progress was
 116         cancelled. This can happen if the user pressed Esc key while
 117         dragging the mouse or the mouse capture was lost for some other
 118         reason. You only need to handle this event if your application
 119         entered into some modal mode when resizing or reordering began, in
 120         which case it should handle this event in addition to the matching
 121         end resizing or reordering ones.
 122     @endEventTable
 123
 124     @library{wxcore}
 125     @category{ctrl}
 126
 127     @see wxGrid, wxListCtrl, wxDataViewCtrl
 128 */
 129 class wxHeaderCtrl : public wxControl
 130 {
 131 public:
 132     /**
 133         Default constructor not creating the underlying window.
 134
 135         You must use Create() after creating the object using this constructor.
 136      */
 137     wxHeaderCtrl();
 138
 139     /**
 140         Constructor creating the window.
 141
 142         Please see Create() for the parameters documentation.
 143      */
 144     wxHeaderCtrl(wxWindow *parent,
 145                  wxWindowID winid = wxID_ANY,
 146                  const wxPoint& pos = wxDefaultPosition,
 147                  const wxSize& size = wxDefaultSize,
 148                  long style = wxHD_DEFAULT_STYLE,
 149                  const wxString& name = wxHeaderCtrlNameStr);
 150
 151     /**
 152         Create the header control window.
 153
 154         @param parent
 155             The parent window. The header control should be typically
 156             positioned along the top edge of this window.
 157         @param winid
 158             Id of the control or @c wxID_ANY if you don't care.
 159         @param pos
 160             The initial position of the control.
 161         @param size
 162             The initial size of the control (usually not very useful as this
 163             control will typically be resized to have the same width as the
 164             associated data display control).
 165         @param style
 166             The control style, @c wxHD_DEFAULT_STYLE by default. Notice that
 167             the default style allows the user to reorder the columns by
 168             dragging them and you need to explicitly turn this feature off by
 169             using @code wxHD_DEFAULT_STYLE & ~wxHD_ALLOW_REORDER @endcode if
 170             this is undesirable.
 171         @param name
 172             The name of the control.
 173      */
 174     bool Create(wxWindow *parent,
 175                 wxWindowID winid = wxID_ANY,
 176                 const wxPoint& pos = wxDefaultPosition,
 177                 const wxSize& size = wxDefaultSize,
 178                 long style = wxHD_DEFAULT_STYLE,
 179                 const wxString& name = wxHeaderCtrlNameStr);
 180
 181     /**
 182         Set the number of columns in the control.
 183
 184         The control will use GetColumn() to get information about all the
 185         new columns and refresh itself, i.e. this method also has the same
 186         effect as calling UpdateColumn() for all columns but it should only be
 187         used if the number of columns really changed.
 188      */
 189     void SetColumnCount(unsigned int count);
 190
 191     /**
 192         Return the number of columns in the control.
 193
 194         @return
 195             Number of columns as previously set by SetColumnCount().
 196
 197         @see IsEmpty()
 198      */
 199     unsigned int GetColumnCount() const;
 200
 201     /**
 202         Return whether the control has any columns.
 203
 204         @see GetColumnCount()
 205      */
 206     bool IsEmpty() const;
 207
 208     /**
 209         Update the column with the given index.
 210
 211         When the value returned by GetColumn() changes, this method must be
 212         called to notify the control about the change and update the visual
 213         display to match the new column data.
 214
 215         @param idx
 216             The column index, must be less than GetColumnCount().
 217      */
 218     void UpdateColumn(unsigned int idx);
 219
 220     /**
 221         Change the columns display order.
 222
 223         The display order defines the order in which the columns appear on the
 224         screen and does @em not affect the interpretation of indices by all the
 225         other class methods.
 226
 227         The @a order array specifies the column indices corresponding to the
 228         display positions.
 229
 230         @param order
 231             A permutation of all column indices, i.e. an array of size
 232             GetColumnsOrder() containing all column indices exactly once. The
 233             n-th element of this array defines the index of the column shown at
 234             the n-th position from left (for the default left-to-right writing
 235             direction).
 236
 237         @see wxListCtrl::SetColumnsOrder()
 238      */
 239     void SetColumnsOrder(const wxArrayInt& order);
 240
 241     /**
 242         Return the array describing the columns display order.
 243
 244         For the controls without wxHD_ALLOW_REORDER style the returned array
 245         will be the same as was passed to SetColumnsOrder() previously or
 246         define the default order (with n-th element being n) if it hadn't been
 247         called. But for the controls with wxHD_ALLOW_REORDER style, the columns
 248         can be also reordered by user.
 249      */
 250     wxArrayInt GetColumnsOrder() const;
 251
 252     /**
 253         Return the index of the column displayed at the given position.
 254
 255         @param pos
 256             The display position, e.g. 0 for the left-most column, 1 for the
 257             next one and so on until GetColumnCount() - 1.
 258
 259         @see GetColumnPos()
 260      */
 261     unsigned int GetColumnAt(unsigned int pos) const;
 262
 263     /**
 264         Get the position at which this column is currently displayed.
 265
 266         Notice that a valid position is returned even for the hidden columns
 267         currently.
 268
 269         @param idx
 270             The column index, must be less than GetColumnCount().
 271
 272         @see GetColumnAt()
 273      */
 274     unsigned int GetColumnPos(unsigned int idx) const;
 275
 276     /**
 277         Reset the columns order to the natural one.
 278
 279         After calling this function, the column with index @c idx appears at
 280         position @c idx in the control.
 281      */
 282     void ResetColumnsOrder();
 283
 284     /**
 285         Helper function to manipulate the array of column indices.
 286
 287         This function reshuffles the array of column indices indexed by
 288         positions (i.e. using the same convention as for SetColumnsOrder()) so
 289         that the column with the given index is found at the specified
 290         position.
 291
 292         @param order
 293             Array containing the indices of columns in order of their
 294             positions.
 295         @param idx
 296             The index of the column to move.
 297         @param pos
 298             The new position for the column @a idx.
 299      */
 300     static void MoveColumnInOrderArray(wxArrayInt& order,
 301                                        unsigned int idx,
 302                                        unsigned int pos);
 303
 304     /**
 305         Show the popup menu allowing the user to show or hide the columns.
 306
 307         This functions shows the popup menu containing all columns with check
 308         marks for the ones which are currently shown and allows the user to
 309         check or uncheck them to toggle their visibility. It is called from the
 310         default EVT_HEADER_RIGHT_CLICK handler for the controls which have
 311         wxHD_ALLOW_HIDE style. And if the column has wxHD_ALLOW_REORDER style
 312         as well, the menu also contains an item to customize the columns shown
 313         using which results in ShowCustomizeDialog() being called, please see
 314         its description for more details.
 315
 316         If a column was toggled, UpdateColumnVisibility() virtual function is
 317         called so it must be implemented for the controls with wxHD_ALLOW_HIDE
 318         style or if you call this function explicitly.
 319
 320         @param pt
 321             The position of the menu, in the header window coordinates.
 322         @param title
 323             The title for the menu if not empty.
 324         @return
 325             @true if a column was shown or hidden or @false if nothing was
 326             done, e.g. because the menu was cancelled.
 327      */
 328     bool ShowColumnsMenu(const wxPoint& pt, const wxString& title = wxString());
 329
 330     /**
 331         Helper function appending the checkable items corresponding to all the
 332         columns to the given menu.
 333
 334         This function is used by ShowColumnsMenu() but can also be used if you
 335         show your own custom columns menu and still want all the columns shown
 336         in it. It appends menu items with column labels as their text and
 337         consecutive ids starting from @a idColumnsBase to the menu and checks
 338         the items corresponding to the currently visible columns.
 339
 340         Example of use:
 341         @code
 342             wxMenu menu;
 343             menu.Append(100, "Some custom command");
 344             menu.AppendSeparator();
 345             AddColumnsItems(menu, 200);
 346             const int rc = GetPopupMenuSelectionFromUser(menu, pt);
 347             if ( rc >= 200 )
 348                 ... toggle visibility of the column rc-200 ...
 349         @endcode
 350
 351         @param menu
 352             The menu to append the items to. It may be currently empty or not.
 353         @param idColumnsBase
 354             The id for the menu item corresponding to the first column, the
 355             other ones are consecutive starting from it. It should be positive.
 356      */
 357     void AddColumnsItems(wxMenu& menu, int idColumnsBase = 0);
 358
 359     /**
 360         Show the column customization dialog.
 361
 362         This function displays a modal dialog containing the list of all
 363         columns which the user can use to reorder them as well as show or hide
 364         individual columns.
 365
 366         If the user accepts the changes done in the dialog, the virtual
 367         methods UpdateColumnVisibility() and UpdateColumnsOrder() will be
 368         called so they must be overridden in the derived class if this method
 369         is ever called. Please notice that the user will be able to invoke it
 370         interactively from the header popup menu if the control has both
 371         wxHD_ALLOW_HIDE and wxHD_ALLOW_REORDER styles.
 372
 373         @see wxRearrangeDialog
 374      */
 375     bool ShowCustomizeDialog();
 376
 377 protected:
 378     /**
 379         Method to be implemented by the derived classes to return the
 380         information for the given column.
 381
 382         @param idx
 383             The column index, between 0 and the value last passed to
 384             SetColumnCount().
 385      */
 386     virtual const wxHeaderColumn& GetColumn(unsigned int idx) const = 0;
 387
 388     /**
 389         Method called when the column visibility is changed by the user.
 390
 391         This method is called from ShowColumnsMenu() or ShowCustomizeDialog()
 392         when the user interactively hides or shows a column. A typical
 393         implementation will simply update the internally stored column state.
 394         Notice that there is no need to call UpdateColumn() from this method as
 395         it is already done by wxHeaderCtrl itself.
 396
 397         The base class version doesn't do anything and must be overridden if
 398         this method is called.
 399
 400         @param idx
 401             The index of the column whose visibility was toggled.
 402         @param show
 403             The new visibility value, @true if the column is now shown or
 404             @false if it is not hidden.
 405      */
 406     virtual void UpdateColumnVisibility(unsigned int idx, bool show);
 407
 408     /**
 409         Method called when the columns order is changed in the customization
 410         dialog.
 411
 412         This method is only called from ShowCustomizeDialog() when the user
 413         changes the order of columns. In particular it is @em not called if a
 414         single column changes place because the user dragged it to the new
 415         location, the EVT_HEADER_END_REORDER event handler should be used to
 416         react to this.
 417
 418         A typical implementation in a derived class will update the display
 419         order of the columns in the associated control, if any. Notice that
 420         there is no need to call SetColumnsOrder() from it as wxHeaderCtrl does
 421         it itself.
 422
 423         The base class version doesn't do anything and must be overridden if
 424         this method is called.
 425
 426         @param order
 427             The new column order. This array uses the same convention as
 428             SetColumnsOrder().
 429      */
 430     virtual void UpdateColumnsOrder(const wxArrayInt& order);
 431
 432     /**
 433         Method which may be implemented by the derived classes to allow double
 434         clicking the column separator to resize the column to fit its contents.
 435
 436         When a separator is double clicked, the default handler of
 437         EVT_HEADER_SEPARATOR_DCLICK event calls this function and refreshes the
 438         column if it returns @true so to implement the resizing of the column
 439         to fit its width on header double click you need to implement this
 440         method using logic similar to this example:
 441         @code
 442             class MyHeaderColumn : public wxHeaderColumn
 443             {
 444             public:
 445                 ...
 446
 447                 void SetWidth(int width) { m_width = width; }
 448                 virtual int GetWidth() const { return m_width; }
 449
 450             private:
 451                 int m_width;
 452             };
 453
 454             class MyHeaderCtrl : public wxHeaderCtrl
 455             {
 456             public:
 457             protected:
 458                 virtual wxHeaderColumn& GetColumn(unsigned int idx) const
 459                 {
 460                     return m_cols[idx];
 461                 }
 462
 463                 virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle)
 464                 {
 465                     int widthContents = ... compute minimal width for column idx ...
 466                     m_cols[idx].SetWidth(wxMax(widthContents, widthTitle));
 467                     return true;
 468                 }
 469
 470                 wxVector<MyHeaderColumn> m_cols;
 471             };
 472         @endcode
 473
 474         Base class version simply returns @false.
 475
 476         @param idx
 477             The zero-based index of the column to update.
 478         @param widthTitle
 479             Contains minimal width needed to display the column header itself
 480             and will usually be used as a starting point for the fitting width
 481             calculation.
 482
 483         @return
 484             @true to indicate that the column was resized, i.e. GetColumn() now
 485             returns the new width value, and so must be refreshed or @false
 486             meaning that the control didn't reach to the separator double click.
 487      */
 488     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 489
 490     /**
 491         Can be overridden in the derived class to update internal data
 492         structures when the number of the columns in the control changes.
 493
 494         This method is called by SetColumnCount() before effectively changing
 495         the number of columns.
 496
 497         The base class version does nothing but it is good practice to still
 498         call it from the overridden version in the derived class.
 499      */
 500     virtual void OnColumnCountChanging(unsigned int count);
 501 };
 502
 503
 504 /**
 505     @class wxHeaderCtrlSimple
 506
 507     wxHeaderCtrlSimple is a concrete header control which can be used directly,
 508     without inheriting from it as you need to do when using wxHeaderCtrl
 509     itself.
 510
 511     When using it, you need to use simple AppendColumn(), InsertColumn() and
 512     DeleteColumn() methods instead of setting the number of columns with
 513     SetColumnCount() and returning the information about them from the
 514     overridden GetColumn().
 515
 516     @library{wxcore}
 517     @category{ctrl}
 518
 519     @see wxHeaderCtrl
 520 */
 521 class wxHeaderCtrlSimple : public wxHeaderCtrl
 522 {
 523 public:
 524     /**
 525         Default constructor not creating the underlying window.
 526
 527         You must use Create() after creating the object using this constructor.
 528      */
 529     wxHeaderCtrlSimple();
 530
 531     /**
 532         Constructor creating the window.
 533
 534         Please see the base class wxHeaderCtrl::Create() method for the
 535         parameters description.
 536      */
 537     wxHeaderCtrlSimple(wxWindow *parent,
 538                        wxWindowID winid = wxID_ANY,
 539                        const wxPoint& pos = wxDefaultPosition,
 540                        const wxSize& size = wxDefaultSize,
 541                        long style = wxHD_DEFAULT_STYLE,
 542                        const wxString& name = wxHeaderCtrlNameStr);
 543
 544     /**
 545         Insert the column at the given position.
 546
 547         @param col
 548             The column to insert. Notice that because of the existence of
 549             implicit conversion from wxString to wxHeaderColumn a string
 550             can be passed directly here.
 551         @param idx
 552             The position of the new column, from 0 to GetColumnCount(). Using
 553             GetColumnCount() means to append the column to the end.
 554
 555         @see AppendColumn()
 556      */
 557     void InsertColumn(const wxHeaderColumnSimple& col, unsigned int idx);
 558
 559     /**
 560         Append the column to the end of the control.
 561
 562         @see InsertColumn()
 563      */
 564     void AppendColumn(const wxHeaderColumnSimple& col);
 565
 566     /**
 567         Delete the column at the given position.
 568
 569         @see InsertColumn(), AppendColumn()
 570      */
 571     void DeleteColumn(unsigned int idx);
 572
 573     /**
 574         Show or hide the column.
 575
 576         Initially the column is shown by default or hidden if it was added with
 577         wxCOL_HIDDEN flag set.
 578
 579         When a column is hidden, it doesn't appear at all on the screen but its
 580         index is still taken into account when working with other columns. E.g.
 581         if there are three columns 0, 1 and 2 and the column 1 is hidden you
 582         still need to use index 2 to refer to the last visible column.
 583
 584         @param idx
 585             The index of the column to show or hide, from 0 to GetColumnCount().
 586         @param show
 587             Indicates whether the column should be shown (default) or hidden.
 588      */
 589     void ShowColumn(unsigned int idx, bool show = true);
 590
 591     /**
 592         Hide the column with the given index.
 593
 594         This is the same as calling @code ShowColumn(idx, false) @endcode.
 595
 596         @param idx
 597             The index of the column to show or hide, from 0 to GetColumnCount().
 598      */
 599     void HideColumn(unsigned int idx);
 600
 601     /**
 602         Update the column sort indicator.
 603
 604         The sort indicator, if shown, is typically an arrow pointing upwards or
 605         downwards depending on whether the control contents is sorted in
 606         ascending or descending order.
 607
 608         @param idx
 609             The column to set the sort indicator for.
 610             If @c -1 is given, then the currently shown sort indicator
 611             will be removed.
 612         @param sortOrder
 613             If @true or @false show the sort indicator corresponding to
 614             ascending or descending sort order respectively.
 615      */
 616     void ShowSortIndicator(unsigned int idx, bool sortOrder = true);
 617
 618     /**
 619         Remove the sort indicator from the column being used as sort key.
 620
 621         @see ShowSortIndicator
 622      */
 623     void RemoveSortIndicator();
 624
 625 protected:
 626     /**
 627         This function can be overridden in the classes deriving from this
 628         control instead of overriding UpdateColumnWidthToFit().
 629
 630         To implement automatic column resizing to fit its contents width when
 631         the column divider is double clicked, you need to simply return the
 632         fitting width for the given column @a idx from this method, the control
 633         will automatically use the biggest value between the one returned from
 634         here and the one needed for the display of the column title itself.
 635
 636         The base class version returns -1 indicating that this function is not
 637         implemented.
 638      */
 639     virtual int GetBestFittingWidth(unsigned int idx) const;
 640 };
 641
 642 /**
 643     @class wxHeaderCtrlEvent
 644
 645     Event class representing the events generated by wxHeaderCtrl.
 646
 647     @library{wxcore}
 648     @category{events}
 649
 650     @see wxHeaderCtrl
 651 */
 652 class wxHeaderCtrlEvent : public wxNotifyEvent
 653 {
 654 public:
 655     /**
 656         Return the index of the column affected by this event.
 657
 658         This method can be called for all header control events.
 659      */
 660     int GetColumn() const;
 661
 662     /**
 663         Return the current width of the column.
 664
 665         This method can only be called for the dragging events.
 666      */
 667     int GetWidth() const;
 668
 669     /**
 670         Return the new order of the column.
 671
 672         This method can only be called for end reorder event for which it
 673         indicates the tentative new position for the column GetColumn()
 674         selected by the user. If the event is not vetoed, this will become the
 675         new column position in wxHeaderCtrl::GetColumnsOrder().
 676      */
 677     unsigned int GetNewOrder() const;
 678 };