interface/wx/scrolwin.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        scrolwin.h
   3 // Purpose:     interface of wxScrolled template
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     Possible values for the second argument of wxScrolled::ShowScrollbars().
  11  */
  12 enum wxScrollbarVisibility
  13 {
  14     wxSHOW_SB_NEVER = -1,   ///< Never show the scrollbar at all.
  15     wxSHOW_SB_DEFAULT,      ///< Show scrollbar only if it is needed.
  16     wxSHOW_SB_ALWAYS        ///< Always show scrollbar, even if not needed.
  17 };
  18
  19 /**
  20
  21     The wxScrolled class manages scrolling for its client area, transforming
  22     the coordinates according to the scrollbar positions, and setting the
  23     scroll positions, thumb sizes and ranges according to the area in view.
  24
  25     There are two commonly used (but not the only possible!) specializations of
  26     this class:
  27
  28     - ::wxScrolledWindow, aka wxScrolled<wxPanel>, is equivalent to
  29       ::wxScrolledWindow from earlier versions. Derived from wxPanel, it shares
  30       wxPanel's behaviour with regard to TAB traversal and focus handling. Use
  31       this if the scrolled window will have child controls.
  32
  33     - ::wxScrolledCanvas, aka wxScrolled<wxWindow>, derives from wxWindow and
  34       so doesn't handle children specially. This is suitable e.g. for
  35       implementing scrollable controls such as tree or list controls.
  36
  37     Starting from version 2.4 of wxWidgets, there are several ways to use a
  38     ::wxScrolledWindow (and now wxScrolled). In particular, there are
  39     three ways to set the size of the scrolling area:
  40
  41     One way is to set the scrollbars directly using a call to SetScrollbars().
  42     This is the way it used to be in any previous version of wxWidgets and it
  43     will be kept for backwards compatibility.
  44
  45     An additional method of manual control, which requires a little less
  46     computation of your own, is to set the total size of the scrolling area by
  47     calling either wxWindow::SetVirtualSize(), or wxWindow::FitInside(), and
  48     setting the scrolling increments for it by calling SetScrollRate().
  49     Scrolling in some orientation is enabled by setting a non-zero increment
  50     for it.
  51
  52     The most automatic and newest way is to simply let sizers determine the
  53     scrolling area. This is now the default when you set an interior sizer into
  54     a wxScrolled with wxWindow::SetSizer().  The scrolling area will be
  55     set to the size requested by the sizer and the scrollbars will be assigned
  56     for each orientation according to the need for them and the scrolling
  57     increment set by SetScrollRate().  As above, scrolling is only enabled in
  58     orientations with a non-zero increment.  You can influence the minimum size
  59     of the scrolled area controlled by a sizer by calling
  60     wxWindow::SetVirtualSizeHints(). (Calling SetScrollbars() has analogous
  61     effects in wxWidgets 2.4 -- in later versions it may not continue to
  62     override the sizer.)
  63
  64     Note that if maximum size hints are still supported by
  65     wxWindow::SetVirtualSizeHints(), use them at your own dire risk. They may
  66     or may not have been removed for 2.4, but it really only makes sense to set
  67     minimum size hints here.  We should probably replace
  68     wxWindow::SetVirtualSizeHints() with wxWindow::SetMinVirtualSize() or
  69     similar and remove it entirely in future.
  70
  71     @todo review docs for this class replacing SetVirtualSizeHints() with
  72           SetMinClientSize().
  73
  74     As with all windows, an application can draw onto a wxScrolled using a
  75     @ref overview_dc "device context".
  76
  77     You have the option of handling the OnPaint handler or overriding the
  78     wxScrolled::OnDraw() function, which is passed a pre-scrolled device
  79     context (prepared by wxScrolled::DoPrepareDC()).
  80
  81     If you don't wish to calculate your own scrolling, you must call
  82     DoPrepareDC() when not drawing from within OnDraw(), to set the device
  83     origin for the device context according to the current scroll position.
  84
  85     A wxScrolled will normally scroll itself and therefore its child windows
  86     as well. It might however be desired to scroll a different window than
  87     itself: e.g. when designing a spreadsheet, you will normally only have to
  88     scroll the (usually white) cell area, whereas the (usually grey) label area
  89     will scroll very differently. For this special purpose, you can call
  90     SetTargetWindow() which means that pressing the scrollbars will scroll a
  91     different window.
  92
  93     Note that the underlying system knows nothing about scrolling coordinates,
  94     so that all system functions (mouse events, expose events, refresh calls
  95     etc) as well as the position of subwindows are relative to the "physical"
  96     origin of the scrolled window. If the user insert a child window at
  97     position (10,10) and scrolls the window down 100 pixels (moving the child
  98     window out of the visible area), the child window will report a position
  99     of (10,-90).
 100
 101     @beginStyleTable
 102     @style{wxHSCROLL}
 103            If this style is specified and ::wxVSCROLL isn't, the window will be
 104            scrollable only in horizontal direction (by default, i.e. if neither
 105            this style nor ::wxVSCROLL is specified, it scrolls in both
 106            directions).
 107     @style{wxVSCROLL}
 108            If this style is specified and ::wxHSCROLL isn't, the window will be
 109            scrollable only in vertical direction (by default, i.e. if neither
 110            this style nor ::wxHSCROLL is specified, it scrolls in both
 111            directions).
 112     @style{wxRETAINED}
 113            Uses a backing pixmap to speed refreshes. Motif only.
 114     @endStyleTable
 115
 116
 117     @beginEventEmissionTable{wxScrollWinEvent}
 118     @event{EVT_SCROLLWIN(func)}
 119         Process all scroll events.
 120     @event{EVT_SCROLLWIN_TOP(func)}
 121         Process @c wxEVT_SCROLLWIN_TOP scroll-to-top events.
 122     @event{EVT_SCROLLWIN_BOTTOM(func)}
 123         Process @c wxEVT_SCROLLWIN_BOTTOM scroll-to-bottom events.
 124     @event{EVT_SCROLLWIN_LINEUP(func)}
 125         Process @c wxEVT_SCROLLWIN_LINEUP line up events.
 126     @event{EVT_SCROLLWIN_LINEDOWN(func)}
 127         Process @c wxEVT_SCROLLWIN_LINEDOWN line down events.
 128     @event{EVT_SCROLLWIN_PAGEUP(func)}
 129         Process @c wxEVT_SCROLLWIN_PAGEUP page up events.
 130     @event{EVT_SCROLLWIN_PAGEDOWN(func)}
 131         Process @c wxEVT_SCROLLWIN_PAGEDOWN page down events.
 132     @event{EVT_SCROLLWIN_THUMBTRACK(func)}
 133         Process @c wxEVT_SCROLLWIN_THUMBTRACK thumbtrack events
 134         (frequent events sent as the user drags the thumbtrack).
 135     @event{EVT_SCROLLWIN_THUMBRELEASE(func)}
 136         Process @c wxEVT_SCROLLWIN_THUMBRELEASE thumb release events.
 137     @endEventTable
 138
 139     @note
 140         Don't confuse wxScrollWinEvents generated by this class with
 141         wxScrollEvent objects generated by wxScrollBar and wxSlider.
 142
 143
 144     @remarks
 145     Use wxScrolled for applications where the user scrolls by a fixed amount,
 146     and where a 'page' can be interpreted to be the current visible portion of
 147     the window. For more sophisticated applications, use the wxScrolled
 148     implementation as a guide to build your own scroll behaviour or use
 149     wxVScrolledWindow or its variants.
 150
 151     @since The wxScrolled template exists since version 2.9.0. In older versions,
 152            only ::wxScrolledWindow (equivalent of wxScrolled<wxPanel>) was
 153            available.
 154
 155     @library{wxcore}
 156     @category{miscwnd}
 157
 158     @see wxScrollBar, wxClientDC, wxPaintDC,
 159          wxVScrolledWindow, wxHScrolledWindow, wxHVScrolledWindow,
 160 */
 161 template<class T>
 162 class wxScrolled : public T
 163 {
 164 public:
 165     /// Default constructor.
 166     wxScrolled();
 167
 168     /**
 169         Constructor.
 170
 171         @param parent
 172             Parent window.
 173         @param id
 174             Window identifier. The value @c wxID_ANY indicates a default value.
 175         @param pos
 176             Window position. If a position of ::wxDefaultPosition is specified
 177             then a default position is chosen.
 178         @param size
 179             Window size. If a size of ::wxDefaultSize is specified then the
 180             window is sized appropriately.
 181         @param style
 182             Window style. See wxScrolled.
 183         @param name
 184             Window name.
 185
 186         @remarks The window is initially created without visible scrollbars.
 187                  Call SetScrollbars() to specify how big the virtual window
 188                  size should be.
 189     */
 190     wxScrolled(wxWindow* parent, wxWindowID id = -1,
 191                const wxPoint& pos = wxDefaultPosition,
 192                const wxSize& size = wxDefaultSize,
 193                long style = wxHSCROLL | wxVSCROLL,
 194                const wxString& name = "scrolledWindow");
 195
 196     /**
 197         Translates the logical coordinates to the device ones. For example, if
 198         a window is scrolled 10 pixels to the bottom, the device coordinates of
 199         the origin are (0, 0) (as always), but the logical coordinates are (0,
 200         10) and so the call to CalcScrolledPosition(0, 10, xx, yy) will return
 201         0 in yy.
 202
 203         @beginWxPerlOnly
 204         In wxPerl this method takes two parameters and returns a
 205         2-element list (xx, yy).
 206         @endWxPerlOnly
 207
 208         @see CalcUnscrolledPosition()
 209     */
 210     void CalcScrolledPosition(int x, int y, int* xx, int* yy) const;
 211     wxPoint CalcScrolledPosition(const wxPoint& pt) const;
 212
 213     /**
 214         Translates the device coordinates to the logical ones. For example, if
 215         a window is scrolled 10 pixels to the bottom, the device coordinates of
 216         the origin are (0, 0) (as always), but the logical coordinates are (0,
 217         10) and so the call to CalcUnscrolledPosition(0, 0, xx, yy) will return
 218         10 in yy.
 219
 220         @beginWxPerlOnly
 221         In wxPerl this method takes two parameters and returns a
 222         2-element list (xx, yy).
 223         @endWxPerlOnly
 224
 225         @see CalcScrolledPosition()
 226     */
 227     void CalcUnscrolledPosition(int x, int y, int* xx, int* yy) const;
 228     wxPoint CalcUnscrolledPosition(const wxPoint& pt) const;
 229
 230     /**
 231         Creates the window for two-step construction. Derived classes
 232         should call or replace this function. See wxScrolled::wxScrolled()
 233         for details.
 234     */
 235     bool Create(wxWindow* parent, wxWindowID id = -1,
 236                 const wxPoint& pos = wxDefaultPosition,
 237                 const wxSize& size = wxDefaultSize,
 238                 long style = wxHSCROLL | wxVSCROLL,
 239                 const wxString& name = "scrolledWindow");
 240
 241     /**
 242         Disable use of keyboard keys for scrolling.
 243
 244         By default cursor movement keys (including Home, End, Page Up and Down)
 245         are used to scroll the window appropriately. If the derived class uses
 246         these keys for something else, e.g. changing the currently selected
 247         item, this function can be used to disable this behaviour as it's not
 248         only not necessary then but can actually be actively harmful if another
 249         object forwards a keyboard event corresponding to one of the above keys
 250         to us using ProcessWindowEvent() because the event will always be
 251         processed which can be undesirable.
 252
 253         @since 2.9.1
 254     */
 255     void DisableKeyboardScrolling();
 256
 257     /**
 258         Call this function to prepare the device context for drawing a scrolled
 259         image.
 260
 261         It sets the device origin according to the current scroll position.
 262         DoPrepareDC() is called automatically within the default @c wxEVT_PAINT
 263         event handler, so your OnDraw() override will be passed an already
 264         'pre-scrolled' device context. However, if you wish to draw from
 265         outside of OnDraw() (e.g. from your own @c wxEVT_PAINT handler), you
 266         must call this function yourself.
 267
 268         For example:
 269         @code
 270         void MyWindow::OnEvent(wxMouseEvent& event)
 271         {
 272           wxClientDC dc(this);
 273           DoPrepareDC(dc);
 274
 275           dc.SetPen(*wxBLACK_PEN);
 276           float x, y;
 277           event.Position(&x, &y);
 278           if (xpos > -1 && ypos > -1 && event.Dragging())
 279           {
 280             dc.DrawLine(xpos, ypos, x, y);
 281           }
 282           xpos = x;
 283           ypos = y;
 284         }
 285         @endcode
 286
 287         Notice that the function sets the origin by moving it relatively to the
 288         current origin position, so you shouldn't change the origin before
 289         calling DoPrepareDC() or, if you do, reset it to (0, 0) later. If you
 290         call DoPrepareDC() immediately after device context creation, as in the
 291         example above, this problem doesn't arise, of course, so it is
 292         customary to do it like this.
 293     */
 294     void DoPrepareDC(wxDC& dc);
 295
 296     /**
 297         Enable or disable physical scrolling in the given direction. Physical
 298         scrolling is the physical transfer of bits up or down the
 299         screen when a scroll event occurs. If the application scrolls by a
 300         variable amount (e.g. if there are different font sizes) then physical
 301         scrolling will not work, and you should switch it off. Note that you
 302         will have to reposition child windows yourself, if physical scrolling
 303         is disabled.
 304
 305         @param xScrolling
 306             If @true, enables physical scrolling in the x direction.
 307         @param yScrolling
 308             If @true, enables physical scrolling in the y direction.
 309
 310         @remarks Physical scrolling may not be available on all platforms. Where
 311                  it is available, it is enabled by default.
 312     */
 313     void EnableScrolling(bool xScrolling, bool yScrolling);
 314
 315     /**
 316         Set the scrollbar visibility.
 317
 318         By default the scrollbar in the corresponding direction is only shown
 319         if it is needed, i.e. if the virtual size of the scrolled window in
 320         this direction is greater than the current physical window size. Using
 321         this function the scrollbar visibility can be changed to be:
 322             - wxSHOW_SB_ALWAYS: To always show the scrollbar, even if it is
 323                 not needed currently (wxALWAYS_SHOW_SB style can be used during
 324                 the window creation to achieve the same effect but it applies
 325                 in both directions).
 326             - wxSHOW_SB_NEVER: To never show the scrollbar at all. In this case
 327                 the program should presumably provide some other way for the
 328                 user to scroll the window.
 329             - wxSHOW_SB_DEFAULT: To restore the default behaviour described
 330                 above.
 331
 332         @param horz
 333             The desired visibility for the horizontal scrollbar.
 334         @param vert
 335             The desired visibility for the vertical scrollbar.
 336
 337         @since 2.9.0
 338      */
 339     void ShowScrollbars(wxScrollbarVisibility horz, wxScrollbarVisibility vert);
 340
 341     /**
 342         Get the number of pixels per scroll unit (line), in each direction, as
 343         set by SetScrollbars(). A value of zero indicates no scrolling in that
 344         direction.
 345
 346         @param xUnit
 347             Receives the number of pixels per horizontal unit.
 348         @param yUnit
 349             Receives the number of pixels per vertical unit.
 350
 351         @beginWxPerlOnly
 352         In wxPerl this method takes no parameters and returns a
 353         2-element list (xUnit, yUnit).
 354         @endWxPerlOnly
 355
 356         @see SetScrollbars(), GetVirtualSize()
 357     */
 358     void GetScrollPixelsPerUnit(int* xUnit, int* yUnit) const;
 359
 360     /**
 361         Get the position at which the visible portion of the window starts.
 362
 363         @param x
 364             Receives the first visible x position in scroll units.
 365         @param y
 366             Receives the first visible y position in scroll units.
 367
 368         @remarks
 369             If either of the scrollbars is not at the home position, @a x
 370             and/or @a y will be greater than zero.
 371             Combined with wxWindow::GetClientSize(), the application can use this
 372             function to efficiently redraw only the visible portion of the window.
 373             The positions are in logical scroll units, not pixels, so to convert
 374             to pixels you will have to multiply by the number of pixels per scroll
 375             increment.
 376
 377         @beginWxPerlOnly
 378         In wxPerl this method takes no parameters and returns a
 379         2-element list (x, y).
 380         @endWxPerlOnly
 381
 382         @see SetScrollbars(), Scroll()
 383     */
 384     void GetViewStart(int* x, int* y) const;
 385
 386     /**
 387         This is a simple overload of GetViewStart(int*,int*); see that function
 388         for more info.
 389     */
 390     wxPoint GetViewStart() const;
 391
 392     /**
 393         Gets the size in device units of the scrollable window area (as
 394         opposed to the client size, which is the area of the window currently
 395         visible).
 396
 397         @param x
 398             Receives the length of the scrollable window, in pixels.
 399         @param y
 400             Receives the height of the scrollable window, in pixels.
 401
 402         @remarks Use wxDC::DeviceToLogicalX() and wxDC::DeviceToLogicalY() to
 403                  translate these units to logical units.
 404
 405         @beginWxPerlOnly
 406         In wxPerl this method takes no parameters and returns a
 407         2-element list (xUnit, yUnit).
 408         @endWxPerlOnly
 409
 410         @see SetScrollbars(), GetScrollPixelsPerUnit()
 411     */
 412     void GetVirtualSize(int* x, int* y) const;
 413
 414     /**
 415         Motif only: @true if the window has a backing bitmap.
 416     */
 417     bool IsRetained() const;
 418
 419     /**
 420         Called by the default paint event handler to allow the application to
 421         define painting behaviour without having to worry about calling
 422         DoPrepareDC().
 423
 424         Instead of overriding this function you may also just process the paint
 425         event in the derived class as usual, but then you will have to call
 426         DoPrepareDC() yourself.
 427     */
 428     virtual void OnDraw(wxDC& dc);
 429
 430     /**
 431         This function is for backwards compatibility only and simply calls
 432         DoPrepareDC() now. Notice that it is not called by the default paint
 433         event handle (DoPrepareDC() is), so overriding this method in your
 434         derived class is useless.
 435     */
 436     void PrepareDC(wxDC& dc);
 437
 438     /**
 439         Scrolls a window so the view start is at the given point.
 440
 441         @param x
 442             The x position to scroll to, in scroll units.
 443         @param y
 444             The y position to scroll to, in scroll units.
 445
 446         @remarks The positions are in scroll units, not pixels, so to convert to
 447                  pixels you will have to multiply by the number of
 448                  pixels per scroll increment. If either parameter is
 449                  ::wxDefaultCoord (-1), that position will be ignored (no change
 450                  in that direction).
 451
 452         @see SetScrollbars(), GetScrollPixelsPerUnit()
 453     */
 454     void Scroll(int x, int y);
 455
 456     /**
 457         This is an overload of Scroll(int,int); see that function for more info.
 458     */
 459     void Scroll(const wxPoint& pt);
 460
 461     /**
 462         Set the horizontal and vertical scrolling increment only. See the
 463         pixelsPerUnit parameter in SetScrollbars().
 464     */
 465     void SetScrollRate(int xstep, int ystep);
 466
 467     /**
 468         Sets up vertical and/or horizontal scrollbars.
 469
 470         The first pair of parameters give the number of pixels per 'scroll
 471         step', i.e. amount moved when the up or down scroll arrows are pressed.
 472         The second pair gives the length of scrollbar in scroll steps, which
 473         sets the size of the virtual window.
 474
 475         @a xPos and @a yPos optionally specify a position to scroll to
 476         immediately.
 477
 478         For example, the following gives a window horizontal and vertical
 479         scrollbars with 20 pixels per scroll step, and a size of 50 steps (1000
 480         pixels) in each direction:
 481         @code
 482         window->SetScrollbars(20, 20, 50, 50);
 483         @endcode
 484
 485         wxScrolled manages the page size itself, using the current client
 486         window size as the page size.
 487
 488         Note that for more sophisticated scrolling applications, for example
 489         where scroll steps may be variable according to the position in the
 490         document, it will be necessary to derive a new class from wxWindow,
 491         overriding OnSize() and adjusting the scrollbars appropriately.
 492
 493         @param pixelsPerUnitX
 494             Pixels per scroll unit in the horizontal direction.
 495         @param pixelsPerUnitY
 496             Pixels per scroll unit in the vertical direction.
 497         @param noUnitsX
 498             Number of units in the horizontal direction.
 499         @param noUnitsY
 500             Number of units in the vertical direction.
 501         @param xPos
 502             Position to initialize the scrollbars in the horizontal direction,
 503             in scroll units.
 504         @param yPos
 505             Position to initialize the scrollbars in the vertical direction, in
 506             scroll units.
 507         @param noRefresh
 508             Will not refresh window if @true.
 509
 510         @see wxWindow::SetVirtualSize()
 511     */
 512     void SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
 513                        int noUnitsX,
 514                        int noUnitsY,
 515                        int xPos = 0,
 516                        int yPos = 0,
 517                        bool noRefresh = false);
 518
 519     /**
 520         Call this function to tell wxScrolled to perform the actual scrolling
 521         on a different window (and not on itself).
 522
 523         This method is useful when only a part of the window should be
 524         scrolled. A typical example is a control consisting of a fixed header
 525         and the scrollable contents window: the scrollbars are attached to the
 526         main window itself, hence it, and not the contents window must be
 527         derived from wxScrolled, but only the contents window scrolls when the
 528         scrollbars are used. To implement such setup, you need to call this
 529         method with the contents window as argument.
 530
 531         Notice that if this method is used, GetSizeAvailableForScrollTarget()
 532         method must be overridden.
 533     */
 534     void SetTargetWindow(wxWindow *window);
 535     wxWindow *GetTargetWindow() const;
 536
 537
 538     void SetTargetRect(const wxRect& rect);
 539     wxRect GetTargetRect() const;
 540
 541     int GetScrollPageSize(int orient) const;
 542     void SetScrollPageSize(int orient, int pageSize);
 543     int GetScrollLines( int orient ) const;
 544     void SetScale(double xs, double ys);
 545     double GetScaleX() const;
 546     double GetScaleY() const;
 547
 548     virtual void AdjustScrollbars();
 549
 550     /**
 551        Are we generating the autoscroll events?
 552      */
 553     bool IsAutoScrolling() const;
 554
 555     /**
 556        Stop generating the scroll events when mouse is held outside the
 557        window.
 558      */
 559     void StopAutoScrolling();
 560
 561     /**
 562        This method can be overridden in a derived class to forbid sending the
 563        auto scroll events - note that unlike StopAutoScrolling() it doesn't
 564        stop the timer, so it will be called repeatedly and will typically
 565        return different values depending on the current mouse position
 566
 567        The base class version just returns true.
 568     */
 569     virtual bool SendAutoScrollEvents(wxScrollWinEvent& event) const;
 570
 571
 572 protected:
 573     /**
 574         Function which must be overridden to implement the size available for
 575         the scroll target for the given size of the main window.
 576
 577         This method must be overridden if SetTargetWindow() is used (it is
 578         never called otherwise). The implementation should decrease the @a size
 579         to account for the size of the non-scrollable parts of the main window
 580         and return only the size available for the scrollable window itself.
 581         E.g. in the example given in SetTargetWindow() documentation the
 582         function would subtract the height of the header window from the
 583         vertical component of @a size.
 584      */
 585     virtual wxSize GetSizeAvailableForScrollTarget(const wxSize& size);
 586 };
 587
 588
 589 /**
 590     Scrolled window derived from wxPanel.
 591
 592     See wxScrolled for a detailed description.
 593
 594     @note Note that because this class derives from wxPanel, it shares its
 595           behaviour with regard to TAB traversal and focus handling (in
 596           particular, it forwards focus to its children). If you don't want
 597           this behaviour, use ::wxScrolledCanvas instead.
 598
 599     @note ::wxScrolledWindow is an alias for wxScrolled<wxPanel> since version
 600           2.9.0. In older versions, it was a standalone class.
 601
 602     @library{wxcore}
 603     @category{miscwnd}
 604
 605     @see wxScrolled, ::wxScrolledCanvas
 606 */
 607 typedef wxScrolled<wxPanel> wxScrolledWindow;
 608
 609 /**
 610     Alias for wxScrolled<wxWindow>. Scrolled window that doesn't have children
 611     and so doesn't need or want special handling of TAB traversal.
 612
 613     @since 2.9.0
 614
 615     @library{wxcore}
 616     @category{miscwnd}
 617
 618     @see wxScrolled, ::wxScrolledWindow
 619 */
 620 typedef wxScrolled<wxWindow> wxScrolledCanvas;