1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: wxScrolledWindow sample
4 // Author: Robert Roebling
6 // Copyright: (C) 1998 Robert Roebling, 2002 Ron Lee, 2003 Matt Gregory
7 // (C) 2008 Vadim Zeitlin
8 // Licence: wxWindows license
9 /////////////////////////////////////////////////////////////////////////////
11 #include "wx/wxprec.h"
23 #include "wx/tglbtn.h"
25 // ----------------------------------------------------------------------------
27 // ----------------------------------------------------------------------------
29 // MySimpleCanvas: a scrolled window which draws a simple rectangle
30 class MySimpleCanvas
: public wxScrolledWindow
35 // these numbers are not multiple of 10 (our scroll step) to test for
36 // the absence of rounding errors (e.g. we should have one more page
37 // than WIDTH/10 to show the right side of the rectangle)
42 MySimpleCanvas(wxWindow
*parent
)
43 : wxScrolledWindow(parent
, wxID_ANY
)
45 SetScrollRate( 10, 10 );
46 SetVirtualSize( WIDTH
, HEIGHT
);
47 SetBackgroundColour( *wxWHITE
);
49 Connect(wxEVT_PAINT
, wxPaintEventHandler(MySimpleCanvas::OnPaint
));
53 void OnPaint(wxPaintEvent
& WXUNUSED(event
))
57 // this call is vital: it adjusts the dc to account for the current
61 dc
.SetPen( *wxRED_PEN
);
62 dc
.SetBrush( *wxTRANSPARENT_BRUSH
);
63 dc
.DrawRectangle( 0, 0, WIDTH
, HEIGHT
);
68 // MySimpleFrame: a frame which contains a MySimpleCanvas
69 class MySimpleFrame
: public wxFrame
72 MySimpleFrame(wxWindow
*parent
)
73 : wxFrame(parent
, wxID_ANY
, "MySimpleCanvas")
75 new MySimpleCanvas(this);
77 // ensure that we have scrollbars initially
78 SetClientSize(MySimpleCanvas::WIDTH
/2, MySimpleCanvas::HEIGHT
/2);
84 // ----------------------------------------------------------------------
85 // a more complex example
86 // ----------------------------------------------------------------------
89 class MyCanvas
: public wxScrolledWindow
92 MyCanvas(wxWindow
*parent
);
95 void OnPaint(wxPaintEvent
& event
);
96 void OnQueryPosition(wxCommandEvent
& event
);
97 void OnAddButton(wxCommandEvent
& event
);
98 void OnDeleteButton(wxCommandEvent
& event
);
99 void OnMoveButton(wxCommandEvent
& event
);
100 void OnScrollWin(wxCommandEvent
& event
);
101 void OnMouseRightDown(wxMouseEvent
& event
);
102 void OnMouseWheel(wxMouseEvent
& event
);
106 DECLARE_EVENT_TABLE()
109 class MyCanvasFrame
: public wxFrame
112 MyCanvasFrame(wxWindow
*parent
)
113 : wxFrame(parent
, wxID_ANY
, "MyCanvas")
115 m_canvas
= new MyCanvas(this);
117 wxMenu
*menuFile
= new wxMenu();
118 menuFile
->Append(wxID_DELETE
, "&Delete all");
119 menuFile
->Append(wxID_NEW
, "Insert &new");
121 wxMenuBar
*mbar
= new wxMenuBar();
122 mbar
->Append(menuFile
, "&File");
125 Connect(wxID_DELETE
, wxEVT_COMMAND_MENU_SELECTED
,
126 wxCommandEventHandler(MyCanvasFrame::OnDeleteAll
));
127 Connect(wxID_NEW
, wxEVT_COMMAND_MENU_SELECTED
,
128 wxCommandEventHandler(MyCanvasFrame::OnInsertNew
));
134 void OnDeleteAll(wxCommandEvent
& WXUNUSED(event
))
136 m_canvas
->DestroyChildren();
139 void OnInsertNew(wxCommandEvent
& WXUNUSED(event
))
141 (void)new wxButton(m_canvas
, wxID_ANY
, "Hello", wxPoint(100,100));
147 // ----------------------------------------------------------------------------
148 // example using sizers with wxScrolledWindow
149 // ----------------------------------------------------------------------------
151 const wxSize
SMALL_BUTTON( 100, 50 );
152 const wxSize
LARGE_BUTTON( 300, 200 );
154 class MySizerScrolledWindow
: public wxScrolledWindow
157 MySizerScrolledWindow(wxWindow
*parent
);
160 // this button can be clicked to change its own size in the handler below,
161 // the window size will be automatically adjusted to fit the button
164 void OnResizeClick(wxCommandEvent
& event
);
167 class MySizerFrame
: public wxFrame
170 MySizerFrame(wxWindow
*parent
)
171 : wxFrame(parent
, wxID_ANY
, "MySizerScrolledWindow")
173 new MySizerScrolledWindow(this);
175 // ensure that the scrollbars appear when the button becomes large
176 SetClientSize(LARGE_BUTTON
/2);
181 // ----------------------------------------------------------------------------
182 // example showing scrolling only part of the window
183 // ----------------------------------------------------------------------------
185 // this window consists of an empty space in its corner, column labels window
186 // along its top, row labels window along its left hand side and a canvas in
187 // the remaining space
189 class MySubColLabels
: public wxWindow
192 MySubColLabels(wxScrolledWindow
*parent
)
193 : wxWindow(parent
, wxID_ANY
)
197 Connect(wxEVT_PAINT
, wxPaintEventHandler(MySubColLabels::OnPaint
));
201 void OnPaint(wxPaintEvent
& WXUNUSED(event
))
205 // This is wrong.. it will translate both x and y if the
206 // window is scrolled, the label windows are active in one
207 // direction only. Do the action below instead -- RL.
208 //m_owner->PrepareDC( dc );
210 int xScrollUnits
, xOrigin
;
212 m_owner
->GetViewStart( &xOrigin
, 0 );
213 m_owner
->GetScrollPixelsPerUnit( &xScrollUnits
, 0 );
214 dc
.SetDeviceOrigin( -xOrigin
* xScrollUnits
, 0 );
216 dc
.DrawText("Column 1", 5, 5);
217 dc
.DrawText("Column 2", 105, 5);
218 dc
.DrawText("Column 3", 205, 5);
221 wxScrolledWindow
*m_owner
;
224 class MySubRowLabels
: public wxWindow
227 MySubRowLabels(wxScrolledWindow
*parent
)
228 : wxWindow(parent
, wxID_ANY
)
232 Connect(wxEVT_PAINT
, wxPaintEventHandler(MySubRowLabels::OnPaint
));
236 void OnPaint(wxPaintEvent
& WXUNUSED(event
))
240 // This is wrong.. it will translate both x and y if the
241 // window is scrolled, the label windows are active in one
242 // direction only. Do the action below instead -- RL.
243 //m_owner->PrepareDC( dc );
245 int yScrollUnits
, yOrigin
;
247 m_owner
->GetViewStart( 0, &yOrigin
);
248 m_owner
->GetScrollPixelsPerUnit( 0, &yScrollUnits
);
249 dc
.SetDeviceOrigin( 0, -yOrigin
* yScrollUnits
);
251 dc
.DrawText("Row 1", 5, 5);
252 dc
.DrawText("Row 2", 5, 30);
253 dc
.DrawText("Row 3", 5, 55);
254 dc
.DrawText("Row 4", 5, 80);
255 dc
.DrawText("Row 5", 5, 105);
256 dc
.DrawText("Row 6", 5, 130);
259 wxScrolledWindow
*m_owner
;
262 class MySubCanvas
: public wxPanel
265 MySubCanvas(wxScrolledWindow
*parent
, wxWindow
*cols
, wxWindow
*rows
)
266 : wxPanel(parent
, wxID_ANY
)
272 (void)new wxButton(this, wxID_ANY
, "Hallo I",
273 wxPoint(0,50), wxSize(100,25) );
274 (void)new wxButton(this, wxID_ANY
, "Hallo II",
275 wxPoint(200,50), wxSize(100,25) );
277 (void)new wxTextCtrl(this, wxID_ANY
, "Text I",
278 wxPoint(0,100), wxSize(100,25) );
279 (void)new wxTextCtrl(this, wxID_ANY
, "Text II",
280 wxPoint(200,100), wxSize(100,25) );
282 (void)new wxComboBox(this, wxID_ANY
, "ComboBox I",
283 wxPoint(0,150), wxSize(100,25));
284 (void)new wxComboBox(this, wxID_ANY
, "ComboBox II",
285 wxPoint(200,150), wxSize(100,25));
287 SetBackgroundColour("WHEAT");
289 Connect(wxEVT_PAINT
, wxPaintEventHandler(MySubCanvas::OnPaint
));
292 // override the base class function so that when this window is scrolled,
293 // the labels are scrolled in sync
294 virtual void ScrollWindow(int dx
, int dy
, const wxRect
*rect
)
296 wxPanel::ScrollWindow( dx
, dy
, rect
);
297 m_colLabels
->ScrollWindow( dx
, 0, rect
);
298 m_rowLabels
->ScrollWindow( 0, dy
, rect
);
302 void OnPaint(wxPaintEvent
& WXUNUSED(event
))
304 wxPaintDC
dc( this );
305 m_owner
->PrepareDC( dc
);
307 dc
.SetPen( *wxBLACK_PEN
);
309 // OK, let's assume we are a grid control and we have two
310 // grid cells. Here in OnPaint we want to know which cell
311 // to redraw so that we prevent redrawing cells that don't
312 // need to get redrawn. We have one cell at (0,0) and one
313 // more at (200,0), both having a size of (100,25).
315 // We can query how much the window has been scrolled
316 // by calling CalcUnscrolledPosition()
320 m_owner
->CalcUnscrolledPosition( scroll_x
, scroll_y
, &scroll_x
, &scroll_y
);
322 // We also need to know the size of the window to see which
323 // cells are completely hidden and not get redrawn
327 GetClientSize( &size_x
, &size_y
);
329 // First cell: (0,0)(100,25)
331 if ((0+100-scroll_x
> 0) && (0+25-scroll_y
> 0) &&
332 (0-scroll_x
< size_x
) && (0-scroll_y
< size_y
))
334 // Has the region on screen been exposed?
335 if (IsExposed(0,0,100,25))
337 dc
.DrawRectangle( 0, 0, 100, 25 );
338 dc
.DrawText("First Cell", 5, 5);
343 // Second cell: (0,200)(100,25)
345 if ((200+100-scroll_x
> 0) && (0+25-scroll_y
> 0) &&
346 (200-scroll_x
< size_x
) && (0-scroll_y
< size_y
))
348 // Has the region on screen been exposed?
349 if (IsExposed(200,0,100,25))
351 dc
.DrawRectangle( 200, 0, 100, 25 );
352 dc
.DrawText("Second Cell", 205, 5);
357 wxScrolledWindow
*m_owner
;
358 wxWindow
*m_colLabels
,
362 class MySubScrolledWindow
: public wxScrolledWindow
371 MySubScrolledWindow(wxWindow
*parent
)
372 : wxScrolledWindow(parent
, wxID_ANY
)
374 // create the children
375 MySubColLabels
*cols
= new MySubColLabels(this);
376 MySubRowLabels
*rows
= new MySubRowLabels(this);
378 m_canvas
= new MySubCanvas(this, cols
, rows
);
381 wxFlexGridSizer
*sizer
= new wxFlexGridSizer(2, 2, 10, 10);
382 sizer
->Add(CORNER_WIDTH
, CORNER_HEIGHT
); // just a spacer
383 sizer
->Add(cols
, wxSizerFlags().Expand());
384 sizer
->Add(rows
, wxSizerFlags().Expand());
385 sizer
->Add(m_canvas
, wxSizerFlags().Expand());
386 sizer
->AddGrowableRow(1);
387 sizer
->AddGrowableCol(1);
390 // this is the key call: it means that only m_canvas will be scrolled
391 // and not this window itself
392 SetTargetWindow(m_canvas
);
394 SetScrollbars(10, 10, 50, 50);
396 Connect(wxEVT_SIZE
, wxSizeEventHandler(MySubScrolledWindow::OnSize
));
400 // scrolled windows which use scroll target different from the window
401 // itself must override this virtual method
402 virtual wxSize
GetSizeAvailableForScrollTarget(const wxSize
& size
)
404 // decrease the total size by the size of the non-scrollable parts
405 // above/to the left of the canvas
406 wxSize
sizeCanvas(size
);
413 void OnSize(wxSizeEvent
& WXUNUSED(event
))
415 // We need to override OnSize so that our scrolled
416 // window a) does call Layout() to use sizers for
417 // positioning the controls but b) does not query
418 // the sizer for their size and use that for setting
419 // the scrollable area as set that ourselves by
420 // calling SetScrollbar() further down.
427 MySubCanvas
*m_canvas
;
430 class MySubFrame
: public wxFrame
433 MySubFrame(wxWindow
*parent
)
434 : wxFrame(parent
, wxID_ANY
, "MySubScrolledWindow")
436 new MySubScrolledWindow(this);
442 // ----------------------------------------------------------------------------
443 // more simple examples of wxScrolledWindow usage
444 // ----------------------------------------------------------------------------
446 // base class for both of them
447 class MyScrolledWindowBase
: public wxScrolledWindow
450 MyScrolledWindowBase(wxWindow
*parent
)
451 : wxScrolledWindow(parent
, wxID_ANY
,
452 wxDefaultPosition
, wxDefaultSize
,
460 dc
.GetTextExtent("Line 17", NULL
, &m_hLine
);
463 // this scrolled window can be synchronized with another one: if this
464 // function is called with a non-NULL pointer, the given window will be
465 // scrolled to the same position as this one
466 void SyncWith(MyScrolledWindowBase
*win
)
473 virtual void ScrollWindow(int dx
, int dy
, const wxRect
*rect
= NULL
)
475 wxScrolledWindow::ScrollWindow(dx
, dy
, rect
);
481 // the height of one line on screen
484 // the number of lines we draw
488 bool WasScrolledFirst() const { return m_inDoSync
; }
490 void DoSyncIfNecessary()
492 if ( m_winSync
&& !m_winSync
->WasScrolledFirst() )
496 m_winSync
->Scroll(GetViewStart());
502 // the window to synchronize with this one or NULL
503 MyScrolledWindowBase
*m_winSync
;
505 // the flag preventing infinite recursion which would otherwise happen if
506 // one window synchronized the other one which in turn synchronized this
511 // this class does "stupid" redrawing - it redraws everything each time
512 // and sets the scrollbar extent directly.
514 class MyScrolledWindowDumb
: public MyScrolledWindowBase
517 MyScrolledWindowDumb(wxWindow
*parent
) : MyScrolledWindowBase(parent
)
520 SetScrollbars(0, m_hLine
, 0, m_nLines
+ 1, 0, 0, true /* no refresh */);
523 virtual void OnDraw(wxDC
& dc
);
526 // this class does "smart" redrawing - only redraws the lines which must be
527 // redrawn and sets the scroll rate and virtual size to affect the
530 // Note that this class should produce identical results to the one above.
532 class MyScrolledWindowSmart
: public MyScrolledWindowBase
535 MyScrolledWindowSmart(wxWindow
*parent
) : MyScrolledWindowBase(parent
)
538 SetScrollRate( 0, m_hLine
);
539 SetVirtualSize( wxDefaultCoord
, ( m_nLines
+ 1 ) * m_hLine
);
542 virtual void OnDraw(wxDC
& dc
);
545 // ----------------------------------------------------------------------------
546 // implements a text viewer with simple block selection to test auto-scrolling
548 // ----------------------------------------------------------------------------
550 class MyAutoScrollingWindow
: public wxScrolledWindow
553 MyAutoScrollingWindow( wxWindow
* parent
);
554 wxRect
DeviceCoordsToGraphicalChars(wxRect updRect
) const;
555 wxPoint
DeviceCoordsToGraphicalChars(wxPoint pos
) const;
556 wxPoint
GraphicalCharToDeviceCoords(wxPoint pos
) const;
557 wxRect
LogicalCoordsToGraphicalChars(wxRect updRect
) const;
558 wxPoint
LogicalCoordsToGraphicalChars(wxPoint pos
) const;
559 wxPoint
GraphicalCharToLogicalCoords(wxPoint pos
) const;
561 bool IsSelected(int chX
, int chY
) const;
562 static bool IsInside(int k
, int bound1
, int bound2
);
563 static wxRect
DCNormalize(int x
, int y
, int w
, int h
);
567 void OnDraw(wxDC
& dc
);
568 void OnMouseLeftDown(wxMouseEvent
& event
);
569 void OnMouseLeftUp(wxMouseEvent
& event
);
570 void OnMouseMove(wxMouseEvent
& event
);
571 void OnMouseCaptureLost(wxMouseCaptureLostEvent
& event
);
572 void OnScroll(wxScrollWinEvent
& event
);
574 // test data variables
575 static const char* sm_testData
;
576 static const int sm_lineCnt
; // line count
577 static const int sm_lineLen
; // line length in characters
578 // sizes for graphical data
579 int m_fontH
, m_fontW
;
580 // selection tracking
581 wxPoint m_selStart
; // beginning of blockwise selection
582 wxPoint m_cursor
; // end of blockwise selection (mouse position)
588 DECLARE_EVENT_TABLE()
591 class MyAutoFrame
: public wxFrame
594 MyAutoFrame(wxWindow
*parent
)
595 : wxFrame(parent
, wxID_ANY
, "MyAutoScrollingWindow")
597 new MyAutoScrollingWindow(this);
604 // ----------------------------------------------------------------------------
605 // MyFrame: the main application frame showing all the classes above
606 // ----------------------------------------------------------------------------
608 class MyFrame
: public wxFrame
614 void OnAbout(wxCommandEvent
& event
);
615 void OnQuit(wxCommandEvent
& event
);
617 void OnTestSimple(wxCommandEvent
& WXUNUSED(event
)) { new MySimpleFrame(this); }
618 void OnTestCanvas(wxCommandEvent
& WXUNUSED(event
)) { new MyCanvasFrame(this); }
619 void OnTestSizer(wxCommandEvent
& WXUNUSED(event
)) { new MySizerFrame(this); }
620 void OnTestSub(wxCommandEvent
& WXUNUSED(event
)) { new MySubFrame(this); }
621 void OnTestAuto(wxCommandEvent
& WXUNUSED(event
)) { new MyAutoFrame(this); }
623 void OnToggleSync(wxCommandEvent
& event
);
625 MyScrolledWindowBase
*m_win1
,
628 DECLARE_EVENT_TABLE()
631 // ----------------------------------------------------------------------------
633 // ----------------------------------------------------------------------------
635 class MyApp
: public wxApp
638 virtual bool OnInit();
642 // ============================================================================
644 // ============================================================================
646 // ----------------------------------------------------------------------------
648 // ----------------------------------------------------------------------------
650 const wxWindowID ID_ADDBUTTON
= wxWindow::NewControlId();
651 const wxWindowID ID_DELBUTTON
= wxWindow::NewControlId();
652 const wxWindowID ID_MOVEBUTTON
= wxWindow::NewControlId();
653 const wxWindowID ID_SCROLLWIN
= wxWindow::NewControlId();
654 const wxWindowID ID_QUERYPOS
= wxWindow::NewControlId();
656 const wxWindowID ID_NEWBUTTON
= wxWindow::NewControlId();
658 BEGIN_EVENT_TABLE(MyCanvas
, wxScrolledWindow
)
659 EVT_PAINT( MyCanvas::OnPaint
)
660 EVT_RIGHT_DOWN( MyCanvas::OnMouseRightDown
)
661 EVT_MOUSEWHEEL( MyCanvas::OnMouseWheel
)
662 EVT_BUTTON( ID_QUERYPOS
, MyCanvas::OnQueryPosition
)
663 EVT_BUTTON( ID_ADDBUTTON
, MyCanvas::OnAddButton
)
664 EVT_BUTTON( ID_DELBUTTON
, MyCanvas::OnDeleteButton
)
665 EVT_BUTTON( ID_MOVEBUTTON
, MyCanvas::OnMoveButton
)
666 EVT_BUTTON( ID_SCROLLWIN
, MyCanvas::OnScrollWin
)
669 MyCanvas::MyCanvas(wxWindow
*parent
)
670 : wxScrolledWindow(parent
, wxID_ANY
,
671 wxDefaultPosition
, wxDefaultSize
,
672 wxSUNKEN_BORDER
| wxTAB_TRAVERSAL
)
674 // you can use either a single SetScrollbars() call or these 2 functions,
675 // usually using them is better because you normally won't need to change
676 // the scroll rate in the future and the sizer can be used to update the
677 // virtual size automatically
678 SetScrollRate( 10, 10 );
679 SetVirtualSize( 500, 1000 );
681 (void) new wxButton( this, ID_ADDBUTTON
, "add button", wxPoint(10,10) );
682 (void) new wxButton( this, ID_DELBUTTON
, "del button", wxPoint(10,40) );
683 (void) new wxButton( this, ID_MOVEBUTTON
, "move button", wxPoint(150,10) );
684 (void) new wxButton( this, ID_SCROLLWIN
, "scroll win", wxPoint(250,10) );
686 wxPanel
*test
= new wxPanel( this, wxID_ANY
,
687 wxPoint(10, 110), wxSize(130,50),
688 wxSIMPLE_BORDER
| wxTAB_TRAVERSAL
);
689 test
->SetBackgroundColour( "WHEAT" );
691 SetBackgroundColour( "BLUE" );
694 void MyCanvas::OnMouseRightDown( wxMouseEvent
&event
)
696 wxPoint
pt( event
.GetPosition() );
698 CalcUnscrolledPosition( pt
.x
, pt
.y
, &x
, &y
);
699 wxLogMessage("Mouse down event at: %d %d, scrolled: %d %d",
703 void MyCanvas::OnMouseWheel( wxMouseEvent
&event
)
705 wxPoint
pt( event
.GetPosition() );
707 CalcUnscrolledPosition( pt
.x
, pt
.y
, &x
, &y
);
708 wxLogMessage( "Mouse wheel event at: %d %d, scrolled: %d %d\n"
709 "Rotation: %d, delta = %d",
711 event
.GetWheelRotation(), event
.GetWheelDelta() );
716 void MyCanvas::OnPaint( wxPaintEvent
&WXUNUSED(event
) )
718 wxPaintDC
dc( this );
721 dc
.DrawText( "Press right mouse button to test calculations!", 160, 50 );
723 dc
.DrawText( "Some text", 140, 140 );
725 dc
.DrawRectangle( 100, 160, 200, 200 );
728 void MyCanvas::OnQueryPosition( wxCommandEvent
&WXUNUSED(event
) )
730 wxPoint
pt( m_button
->GetPosition() );
731 wxLogMessage( "Position of \"Query position\" is %d %d", pt
.x
, pt
.y
);
732 pt
= ClientToScreen( pt
);
733 wxLogMessage("Position of \"Query position\" on screen is %d %d",
737 void MyCanvas::OnAddButton( wxCommandEvent
&WXUNUSED(event
) )
739 wxLogMessage( "Inserting button at position 10,70..." );
740 wxButton
*button
= new wxButton( this, ID_NEWBUTTON
, "new button",
741 wxPoint(10,70), wxSize(80,25) );
742 wxPoint
pt( button
->GetPosition() );
743 wxLogMessage( "-> Position after inserting %d %d", pt
.x
, pt
.y
);
746 void MyCanvas::OnDeleteButton( wxCommandEvent
&WXUNUSED(event
) )
748 wxLogMessage( "Deleting button inserted with \"Add button\"..." );
749 wxWindow
*win
= FindWindow( ID_NEWBUTTON
);
753 wxLogMessage( "-> No window with id = ID_NEWBUTTON found." );
756 void MyCanvas::OnMoveButton( wxCommandEvent
&event
)
758 wxLogMessage( "Moving button 10 pixels downward.." );
759 wxWindow
*win
= FindWindow( event
.GetId() );
760 wxPoint
pt( win
->GetPosition() );
761 wxLogMessage( "-> Position before move is %d %d", pt
.x
, pt
.y
);
762 win
->Move( wxDefaultCoord
, pt
.y
+ 10 );
763 pt
= win
->GetPosition();
764 wxLogMessage( "-> Position after move is %d %d", pt
.x
, pt
.y
);
767 void MyCanvas::OnScrollWin( wxCommandEvent
&WXUNUSED(event
) )
769 wxLogMessage("Scrolling 2 units up.\n"
770 "The white square and the controls should move equally!");
771 Scroll( wxDefaultCoord
, GetViewStart().y
+2 );
774 // ----------------------------------------------------------------------------
775 // MySizerScrolledWindow
776 // ----------------------------------------------------------------------------
778 MySizerScrolledWindow::MySizerScrolledWindow(wxWindow
*parent
)
779 : wxScrolledWindow(parent
)
781 SetBackgroundColour( "GREEN" );
783 // Set the rate we'd like for scrolling.
785 SetScrollRate( 5, 5 );
787 // Populate a sizer with a 'resizing' button and some other static
790 wxFlexGridSizer
*sizer
= new wxFlexGridSizer(2);
792 m_button
= new wxButton( this, wxID_RESIZE_FRAME
, "Press me",
793 wxDefaultPosition
, SMALL_BUTTON
);
795 sizer
->Add(m_button
, wxSizerFlags().Centre().Border(20));
796 sizer
->Add(new wxStaticText(this, wxID_ANY
, "This is just"),
797 wxSizerFlags().Centre());
798 sizer
->Add(new wxStaticText(this, wxID_ANY
, "some decoration"),
799 wxSizerFlags().Centre());
800 sizer
->Add(new wxStaticText(this, wxID_ANY
, "for you to scroll..."),
801 wxSizerFlags().Centre());
803 // Then use the sizer to set the scrolled region size.
807 Connect(wxID_RESIZE_FRAME
, wxEVT_COMMAND_BUTTON_CLICKED
,
808 wxCommandEventHandler(MySizerScrolledWindow::OnResizeClick
));
811 void MySizerScrolledWindow::OnResizeClick(wxCommandEvent
&WXUNUSED(event
))
813 // Arbitrarily resize the button to change the minimum size of
814 // the (scrolled) sizer.
816 if ( m_button
->GetSize() == SMALL_BUTTON
)
817 m_button
->SetSizeHints(LARGE_BUTTON
);
819 m_button
->SetSizeHints(SMALL_BUTTON
);
821 // Force update layout and scrollbars, since nothing we do here
822 // necessarily generates a size event which would do it for us.
826 // ----------------------------------------------------------------------------
828 // ----------------------------------------------------------------------------
830 const wxWindowID Scroll_Test_Simple
= wxWindow::NewControlId();
831 const wxWindowID Scroll_Test_Canvas
= wxWindow::NewControlId();
832 const wxWindowID Scroll_Test_Sizers
= wxWindow::NewControlId();
833 const wxWindowID Scroll_Test_Sub
= wxWindow::NewControlId();
834 const wxWindowID Scroll_Test_Auto
= wxWindow::NewControlId();
836 const wxWindowID Scroll_TglBtn_Sync
= wxWindow::NewControlId();
838 BEGIN_EVENT_TABLE(MyFrame
,wxFrame
)
839 EVT_MENU(wxID_ABOUT
, MyFrame::OnAbout
)
840 EVT_MENU(wxID_EXIT
, MyFrame::OnQuit
)
842 EVT_MENU(Scroll_Test_Simple
, MyFrame::OnTestSimple
)
843 EVT_MENU(Scroll_Test_Canvas
, MyFrame::OnTestCanvas
)
844 EVT_MENU(Scroll_Test_Sizers
, MyFrame::OnTestSizer
)
845 EVT_MENU(Scroll_Test_Sub
, MyFrame::OnTestSub
)
846 EVT_MENU(Scroll_Test_Auto
, MyFrame::OnTestAuto
)
848 EVT_TOGGLEBUTTON(Scroll_TglBtn_Sync
, MyFrame::OnToggleSync
)
852 : wxFrame(NULL
, wxID_ANY
, "wxWidgets scroll sample")
854 wxMenu
*menuFile
= new wxMenu
;
855 menuFile
->Append(wxID_ABOUT
, "&About..");
856 menuFile
->AppendSeparator();
857 menuFile
->Append(wxID_EXIT
, "E&xit\tAlt-X");
859 wxMenu
*menuTest
= new wxMenu
;
860 menuTest
->Append(Scroll_Test_Simple
, "&Simple scroll window\tF1",
861 "Simplest possible scrolled window test.");
862 menuTest
->Append(Scroll_Test_Canvas
, "Scrolled window with &children\tF2",
863 "Scrolled window with controls on it.");
864 menuTest
->Append(Scroll_Test_Sizers
, "Scrolled window with si&zer\tF3",
865 "Scrolled window with children managed by sizer.");
866 menuTest
->Append(Scroll_Test_Sub
, "Scrolled s&ub-window\tF4",
867 "Window only part of which is scrolled.");
868 menuTest
->Append(Scroll_Test_Auto
, "&Auto-scrolled window\tF5",
869 "Window which scrolls when the mouse is held pressed "
872 wxMenuBar
*mbar
= new wxMenuBar
;
873 mbar
->Append(menuFile
, "&File");
874 mbar
->Append(menuTest
, "&Test");
879 const wxSizerFlags
flagsExpand(wxSizerFlags(1).Expand());
881 wxSizer
*topsizer
= new wxBoxSizer(wxVERTICAL
);
882 topsizer
->Add(new wxStaticText(this, wxID_ANY
,
883 "The windows below should behave in the same way, even though\n"
884 "they're implemented quite differently, see the code for details.\n"
886 "The lines redrawn during odd/even repaint iterations are drawn in\n"
887 "red/blue colour to allow seeing immediately how much is repainted,\n"
888 "don't be surprised by this."),
889 wxSizerFlags().Centre().Border());
891 m_win1
= new MyScrolledWindowDumb(this);
892 m_win2
= new MyScrolledWindowSmart(this);
894 wxSizer
*sizerScrollWin
= new wxBoxSizer(wxHORIZONTAL
);
895 sizerScrollWin
->Add(m_win1
, flagsExpand
);
896 sizerScrollWin
->Add(m_win2
, flagsExpand
);
897 topsizer
->Add(sizerScrollWin
, flagsExpand
);
899 wxSizer
*sizerBtns
= new wxBoxSizer(wxHORIZONTAL
);
900 sizerBtns
->Add(new wxToggleButton(this, Scroll_TglBtn_Sync
, "&Synchronize"));
901 topsizer
->Add(sizerBtns
, wxSizerFlags().Centre().Border());
909 void MyFrame::OnToggleSync(wxCommandEvent
& event
)
911 if ( event
.IsChecked() )
913 m_win1
->SyncWith(m_win2
);
914 m_win2
->SyncWith(m_win1
);
918 m_win1
->SyncWith(NULL
);
919 m_win2
->SyncWith(NULL
);
923 void MyFrame::OnQuit(wxCommandEvent
&WXUNUSED(event
))
928 void MyFrame::OnAbout( wxCommandEvent
&WXUNUSED(event
) )
930 (void)wxMessageBox( "wxScrolledWindow sample\n"
932 "Robert Roebling (c) 1998\n"
933 "Vadim Zeitlin (c) 2008\n"
934 "Autoscrolling examples\n"
936 "Auto-timed-scrolling example\n"
937 "Matt Gregory (c) 2003\n",
938 "About wxWidgets scroll sample",
939 wxICON_INFORMATION
| wxOK
);
942 // ----------------------------------------------------------------------------
944 // ----------------------------------------------------------------------------
950 if ( !wxApp::OnInit() )
958 // ----------------------------------------------------------------------------
959 // MyScrolledWindowXXX
960 // ----------------------------------------------------------------------------
962 void MyScrolledWindowDumb::OnDraw(wxDC
& dc
)
964 // this is useful to see which lines are redrawn
965 static size_t s_redrawCount
= 0;
966 dc
.SetTextForeground(s_redrawCount
++ % 2 ? *wxRED
: *wxBLUE
);
969 for ( size_t line
= 0; line
< m_nLines
; line
++ )
972 CalcScrolledPosition(0, y
, NULL
, &yPhys
);
974 dc
.DrawText(wxString::Format("Line %u (logical %d, physical %d)",
975 unsigned(line
), y
, yPhys
), 0, y
);
980 void MyScrolledWindowSmart::OnDraw(wxDC
& dc
)
982 // this is useful to see which lines are redrawn
983 static size_t s_redrawCount
= 0;
984 dc
.SetTextForeground(s_redrawCount
++ % 2 ? *wxRED
: *wxBLUE
);
986 // update region is always in device coords, translate to logical ones
987 wxRect rectUpdate
= GetUpdateRegion().GetBox();
988 CalcUnscrolledPosition(rectUpdate
.x
, rectUpdate
.y
,
989 &rectUpdate
.x
, &rectUpdate
.y
);
991 size_t lineFrom
= rectUpdate
.y
/ m_hLine
,
992 lineTo
= rectUpdate
.GetBottom() / m_hLine
;
994 if ( lineTo
> m_nLines
- 1)
995 lineTo
= m_nLines
- 1;
997 int y
= lineFrom
*m_hLine
;
998 for ( size_t line
= lineFrom
; line
<= lineTo
; line
++ )
1001 CalcScrolledPosition(0, y
, NULL
, &yPhys
);
1003 dc
.DrawText(wxString::Format("Line %u (logical %d, physical %d)",
1004 unsigned(line
), y
, yPhys
), 0, y
);
1009 // ----------------------------------------------------------------------------
1010 // MyAutoScrollingWindow
1011 // ----------------------------------------------------------------------------
1013 BEGIN_EVENT_TABLE(MyAutoScrollingWindow
, wxScrolledWindow
)
1014 EVT_LEFT_DOWN(MyAutoScrollingWindow::OnMouseLeftDown
)
1015 EVT_LEFT_UP(MyAutoScrollingWindow::OnMouseLeftUp
)
1016 EVT_MOTION(MyAutoScrollingWindow::OnMouseMove
)
1017 EVT_MOUSE_CAPTURE_LOST(MyAutoScrollingWindow::OnMouseCaptureLost
)
1018 EVT_SCROLLWIN(MyAutoScrollingWindow::OnScroll
)
1021 MyAutoScrollingWindow::MyAutoScrollingWindow(wxWindow
* parent
)
1022 : wxScrolledWindow(parent
, wxID_ANY
, wxDefaultPosition
, wxDefaultSize
,
1023 wxVSCROLL
| wxHSCROLL
| wxSUNKEN_BORDER
),
1026 m_font(9, wxFONTFAMILY_TELETYPE
, wxFONTSTYLE_NORMAL
, wxFONTWEIGHT_NORMAL
)
1028 wxClientDC
dc(this);
1029 // query dc for text size
1031 dc
.GetTextExtent(wxString("A"), &m_fontW
, &m_fontH
);
1032 // set up the virtual window
1033 SetScrollbars(m_fontW
, m_fontH
, sm_lineLen
, sm_lineCnt
);
1037 MyAutoScrollingWindow::DeviceCoordsToGraphicalChars(wxRect updRect
) const
1039 wxPoint
pos(updRect
.GetPosition());
1040 pos
= DeviceCoordsToGraphicalChars(pos
);
1043 updRect
.width
/= m_fontW
;
1044 updRect
.height
/= m_fontH
;
1045 // the *CoordsToGraphicalChars() funcs round down to upper-left corner,
1046 // so an off-by-one correction is needed
1047 ++updRect
.width
; // kludge
1048 ++updRect
.height
; // kludge
1053 MyAutoScrollingWindow::DeviceCoordsToGraphicalChars(wxPoint pos
) const
1057 pos
+= GetViewStart();
1062 MyAutoScrollingWindow::GraphicalCharToDeviceCoords(wxPoint pos
) const
1064 pos
-= GetViewStart();
1071 MyAutoScrollingWindow::LogicalCoordsToGraphicalChars(wxRect updRect
) const
1073 wxPoint
pos(updRect
.GetPosition());
1074 pos
= LogicalCoordsToGraphicalChars(pos
);
1077 updRect
.width
/= m_fontW
;
1078 updRect
.height
/= m_fontH
;
1079 // the *CoordsToGraphicalChars() funcs round down to upper-left corner,
1080 // so an off-by-one correction is needed
1081 ++updRect
.width
; // kludge
1082 ++updRect
.height
; // kludge
1087 MyAutoScrollingWindow::LogicalCoordsToGraphicalChars(wxPoint pos
) const
1095 MyAutoScrollingWindow::GraphicalCharToLogicalCoords(wxPoint pos
) const
1102 void MyAutoScrollingWindow::MyRefresh()
1104 static wxPoint
lastSelStart(-1, -1), lastCursor(-1, -1);
1105 // refresh last selected area (to deselect previously selected text)
1107 GraphicalCharToDeviceCoords(lastSelStart
),
1108 GraphicalCharToDeviceCoords(lastCursor
)
1110 // off-by-one corrections, necessary because it's not possible to know
1111 // when to round up until rect is normalized by lastUpdRect constructor
1112 lastUpdRect
.width
+= m_fontW
; // kludge
1113 lastUpdRect
.height
+= m_fontH
; // kludge
1114 // refresh currently selected (to select previously unselected text)
1116 GraphicalCharToDeviceCoords(m_selStart
),
1117 GraphicalCharToDeviceCoords(m_cursor
)
1119 // off-by-one corrections
1120 updRect
.width
+= m_fontW
; // kludge
1121 updRect
.height
+= m_fontH
; // kludge
1122 // find necessary refresh areas
1123 int rx
= lastUpdRect
.x
;
1124 int ry
= lastUpdRect
.y
;
1125 int rw
= updRect
.x
- lastUpdRect
.x
;
1126 int rh
= lastUpdRect
.height
;
1128 RefreshRect(DCNormalize(rx
, ry
, rw
, rh
));
1131 ry
= updRect
.y
+ updRect
.height
;
1133 rh
= (lastUpdRect
.y
+ lastUpdRect
.height
) - (updRect
.y
+ updRect
.height
);
1135 RefreshRect(DCNormalize(rx
, ry
, rw
, rh
));
1137 rx
= updRect
.x
+ updRect
.width
;
1139 rw
= (lastUpdRect
.x
+ lastUpdRect
.width
) - (updRect
.x
+ updRect
.width
);
1140 rh
= lastUpdRect
.height
;
1142 RefreshRect(DCNormalize(rx
, ry
, rw
, rh
));
1147 rh
= updRect
.y
- lastUpdRect
.y
;
1149 RefreshRect(DCNormalize(rx
, ry
, rw
, rh
));
1152 lastSelStart
= m_selStart
;
1153 lastCursor
= m_cursor
;
1156 bool MyAutoScrollingWindow::IsSelected(int chX
, int chY
) const
1158 if (IsInside(chX
, m_selStart
.x
, m_cursor
.x
)
1159 && IsInside(chY
, m_selStart
.y
, m_cursor
.y
)) {
1165 bool MyAutoScrollingWindow::IsInside(int k
, int bound1
, int bound2
)
1167 if ((k
>= bound1
&& k
<= bound2
) || (k
>= bound2
&& k
<= bound1
)) {
1174 MyAutoScrollingWindow::DCNormalize(int x
, int y
, int w
, int h
)
1176 // this is needed to get rid of the graphical remnants from the selection
1177 // I think it's because DrawRectangle() excludes a pixel in either direction
1178 const int kludge
= 1;
1179 // make (x, y) the top-left corner
1194 return wxRect(x
, y
, w
, h
);
1197 void MyAutoScrollingWindow::OnDraw(wxDC
& dc
)
1200 wxBrush
normBrush(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW
)
1202 wxBrush
selBrush(wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT
)
1204 dc
.SetPen(*wxTRANSPARENT_PEN
);
1205 const wxString str
= sm_testData
;
1206 size_t strLength
= str
.length();
1207 wxString::const_iterator str_i
;
1209 // draw the characters
1210 // 1. for each update region
1211 for (wxRegionIterator
upd(GetUpdateRegion()); upd
; ++upd
) {
1212 wxRect updRect
= upd
.GetRect();
1213 wxRect
updRectInGChars(DeviceCoordsToGraphicalChars(updRect
));
1214 // 2. for each row of chars in the update region
1215 for (int chY
= updRectInGChars
.y
1216 ; chY
<= updRectInGChars
.y
+ updRectInGChars
.height
; ++chY
) {
1217 // 3. for each character in the row
1218 bool isFirstX
= true;
1219 for (int chX
= updRectInGChars
.x
1220 ; chX
<= updRectInGChars
.x
+ updRectInGChars
.width
1223 if (IsSelected(chX
, chY
)) {
1224 dc
.SetBrush(selBrush
);
1225 dc
.SetTextForeground( wxSystemSettings::GetColour
1226 (wxSYS_COLOUR_HIGHLIGHTTEXT
));
1228 dc
.SetBrush(normBrush
);
1229 dc
.SetTextForeground( wxSystemSettings::GetColour
1230 (wxSYS_COLOUR_WINDOWTEXT
));
1232 // 5. find position info
1233 wxPoint charPos
= GraphicalCharToLogicalCoords(wxPoint
1236 dc
.DrawRectangle(charPos
.x
, charPos
.y
, m_fontW
, m_fontH
);
1237 size_t charIndex
= chY
* sm_lineLen
+ chX
;
1238 if (chY
< sm_lineCnt
&&
1240 charIndex
< strLength
)
1244 str_i
= str
.begin() + charIndex
;
1247 dc
.DrawText(*str_i
, charPos
.x
, charPos
.y
);
1255 void MyAutoScrollingWindow::OnMouseLeftDown(wxMouseEvent
& event
)
1257 // initial press of mouse button sets the beginning of the selection
1258 m_selStart
= DeviceCoordsToGraphicalChars(event
.GetPosition());
1259 // set the cursor to the same position
1260 m_cursor
= m_selStart
;
1261 // draw/erase selection
1265 void MyAutoScrollingWindow::OnMouseLeftUp(wxMouseEvent
& WXUNUSED(event
))
1267 // this test is necessary
1274 void MyAutoScrollingWindow::OnMouseMove(wxMouseEvent
& event
)
1276 // if user is dragging
1277 if (event
.Dragging() && event
.LeftIsDown()) {
1278 // set the new cursor position
1279 m_cursor
= DeviceCoordsToGraphicalChars(event
.GetPosition());
1280 // draw/erase selection
1282 // capture mouse to activate auto-scrolling
1283 if (!HasCapture()) {
1290 MyAutoScrollingWindow::OnMouseCaptureLost(wxMouseCaptureLostEvent
&
1293 // we only capture mouse for timed scrolling, so nothing is needed here
1294 // other than making sure to not call event.Skip()
1297 void MyAutoScrollingWindow::OnScroll(wxScrollWinEvent
& event
)
1299 // need to move the cursor when autoscrolling
1300 // FIXME: the cursor also moves when the scrollbar arrows are clicked
1302 if (event
.GetOrientation() == wxHORIZONTAL
) {
1303 if (event
.GetEventType() == wxEVT_SCROLLWIN_LINEUP
) {
1305 } else if (event
.GetEventType() == wxEVT_SCROLLWIN_LINEDOWN
) {
1308 } else if (event
.GetOrientation() == wxVERTICAL
) {
1309 if (event
.GetEventType() == wxEVT_SCROLLWIN_LINEUP
) {
1311 } else if (event
.GetEventType() == wxEVT_SCROLLWIN_LINEDOWN
) {
1320 const int MyAutoScrollingWindow::sm_lineCnt
= 125;
1321 const int MyAutoScrollingWindow::sm_lineLen
= 79;
1322 const char *MyAutoScrollingWindow::sm_testData
=
1323 "162 Cult of the genius out of vanity. Because we think well of ourselves, but "
1324 "nonetheless never suppose ourselves capable of producing a painting like one of "
1325 "Raphael's or a dramatic scene like one of Shakespeare's, we convince ourselves "
1326 "that the capacity to do so is quite extraordinarily marvelous, a wholly "
1327 "uncommon accident, or, if we are still religiously inclined, a mercy from on "
1328 "high. Thus our vanity, our self-love, promotes the cult of the genius: for only "
1329 "if we think of him as being very remote from us, as a miraculum, does he not "
1330 "aggrieve us (even Goethe, who was without envy, called Shakespeare his star of "
1331 "the most distant heights [\"William! Stern der schonsten Ferne\": from Goethe's, "
1332 "\"Between Two Worlds\"]; in regard to which one might recall the lines: \"the "
1333 "stars, these we do not desire\" [from Goethe's, \"Comfort in Tears\"]). But, aside "
1334 "from these suggestions of our vanity, the activity of the genius seems in no "
1335 "way fundamentally different from the activity of the inventor of machines, the "
1336 "scholar of astronomy or history, the master of tactics. All these activities "
1337 "are explicable if one pictures to oneself people whose thinking is active in "
1338 "one direction, who employ everything as material, who always zealously observe "
1339 "their own inner life and that of others, who perceive everywhere models and "
1340 "incentives, who never tire of combining together the means available to them. "
1341 "Genius too does nothing except learn first how to lay bricks then how to build, "
1342 "except continually seek for material and continually form itself around it. "
1343 "Every activity of man is amazingly complicated, not only that of the genius: "
1344 "but none is a \"miracle.\" Whence, then, the belief that genius exists only in "
1345 "the artist, orator and philosopher? that only they have \"intuition\"? (Whereby "
1346 "they are supposed to possess a kind of miraculous eyeglass with which they can "
1347 "see directly into \"the essence of the thing\"!) It is clear that people speak of "
1348 "genius only where the effects of the great intellect are most pleasant to them "
1349 "and where they have no desire to feel envious. To call someone \"divine\" means: "
1350 "\"here there is no need for us to compete.\" Then, everything finished and "
1351 "complete is regarded with admiration, everything still becoming is undervalued. "
1352 "But no one can see in the work of the artist how it has become; that is its "
1353 "advantage, for wherever one can see the act of becoming one grows somewhat "
1354 "cool. The finished and perfect art of representation repulses all thinking as "
1355 "to how it has become; it tyrannizes as present completeness and perfection. "
1356 "That is why the masters of the art of representation count above all as gifted "
1357 "with genius and why men of science do not. In reality, this evaluation of the "
1358 "former and undervaluation of the latter is only a piece of childishness in the "
1361 "163 The serious workman. Do not talk about giftedness, inborn talents! One can "
1362 "name great men of all kinds who were very little gifted. The acquired "
1363 "greatness, became \"geniuses\" (as we put it), through qualities the lack of "
1364 "which no one who knew what they were would boast of: they all possessed that "
1365 "seriousness of the efficient workman which first learns to construct the parts "
1366 "properly before it ventures to fashion a great whole; they allowed themselves "
1367 "time for it, because they took more pleasure in making the little, secondary "
1368 "things well than in the effect of a dazzling whole. the recipe for becoming a "
1369 "good novelist, for example, is easy to give, but to carry it out presupposes "
1370 "qualities one is accustomed to overlook when one says \"I do not have enough "
1371 "talent.\" One has only to make a hundred or so sketches for novels, none longer "
1372 "than two pages but of such distinctness that every word in them is necessary; "
1373 "one should write down anecdotes each day until one has learned how to give them "
1374 "the most pregnant and effective form; one should be tireless in collecting and "
1375 "describing human types and characters; one should above all relate things to "
1376 "others and listen to others relate, keeping one's eyes and ears open for the "
1377 "effect produced on those present, one should travel like a landscape painter or "
1378 "costume designer; one should excerpt for oneself out of the individual sciences "
1379 "everything that will produce an artistic effect when it is well described, one "
1380 "should, finally, reflect on the motives of human actions, disdain no signpost "
1381 "to instruction about them and be a collector of these things by day and night. "
1382 "One should continue in this many-sided exercise some ten years: what is then "
1383 "created in the workshop, however, will be fit to go out into the world. What, "
1384 "however, do most people do? They begin, not with the parts, but with the whole. "
1385 "Perhaps they chance to strike a right note, excite attention and from then on "
1386 "strike worse and worse notes, for good, natural reasons. Sometimes, when the "
1387 "character and intellect needed to formulate such a life-plan are lacking, fate "
1388 "and need take their place and lead the future master step by step through all "
1389 "the stipulations of his trade. "
1391 "164 Peril and profit in the cult of the genius. The belief in great, superior, "
1392 "fruitful spirits is not necessarily, yet nonetheless is very frequently "
1393 "associated with that religious or semi-religious superstition that these "
1394 "spirits are of supra-human origin and possess certain miraculous abilities by "
1395 "virtue of which they acquire their knowledge by quite other means than the rest "
1396 "of mankind. One ascribes to them, it seems, a direct view of the nature of the "
1397 "world, as it were a hole in the cloak of appearance, and believes that, by "
1398 "virtue of this miraculous seer's vision, they are able to communicate something "
1399 "conclusive and decisive about man and the world without the toil and "
1400 "rigorousness required by science. As long as there continue to be those who "
1401 "believe in the miraculous in the domain of knowledge one can perhaps concede "
1402 "that these people themselves derive some benefit from their belief, inasmuch as "
1403 "through their unconditional subjection to the great spirits they create for "
1404 "their own spirit during its time of development the finest form of discipline "
1405 "and schooling. On the other hand, it is at least questionable whether the "
1406 "superstitious belief in genius, in its privileges and special abilities, is of "
1407 "benefit to the genius himself if it takes root in him. It is in any event a "
1408 "dangerous sign when a man is assailed by awe of himself, whether it be the "
1409 "celebrated Caesar's awe of Caesar or the awe of one's own genius now under "
1410 "consideration; when the sacrificial incense which is properly rendered only to "
1411 "a god penetrates the brain of the genius, so that his head begins to swim and "
1412 "he comes to regard himself as something supra-human. The consequences that "
1413 "slowly result are: the feeling of irresponsibility, of exceptional rights, the "
1414 "belief that he confers a favor by his mere presence, insane rage when anyone "
1415 "attempts even to compare him with others, let alone to rate him beneath them, "
1416 "or to draw attention to lapses in his work. Because he ceases to practice "
1417 "criticism of himself, at last one pinion after the other falls out of his "
1418 "plumage: that superstitious eats at the roots of his powers and perhaps even "
1419 "turns him into a hypocrite after his powers have fled from him. For the great "
1420 "spirits themselves it is therefore probably more beneficial if they acquire an "
1421 "insight into the nature and origin of their powers, if they grasp, that is to "
1422 "say, what purely human qualities have come together in them and what fortunate "
1423 "circumstances attended them: in the first place undiminished energy, resolute "
1424 "application to individual goals, great personal courage, then the good fortune "
1425 "to receive an upbringing which offered in the early years the finest teachers, "
1426 "models and methods. To be sure, when their goal is the production of the "
1427 "greatest possible effect, unclarity with regard to oneself and that "
1428 "semi-insanity superadded to it has always achieved much; for what has been "
1429 "admired and envied at all times has been that power in them by virtue of which "
1430 "they render men will-less and sweep them away into the delusion that the "
1431 "leaders they are following are supra-natural. Indeed, it elevates and inspires "
1432 "men to believe that someone is in possession of supra-natural powers: to this "
1433 "extent Plato was right to say [Plato: Phaedrus, 244a] that madness has brought "
1434 "the greatest of blessings upon mankind. In rare individual cases this portion "
1435 "of madness may, indeed, actually have been the means by which such a nature, "
1436 "excessive in all directions, was held firmly together: in the life of "
1437 "individuals, too, illusions that are in themselves poisons often play the role "
1438 "of healers; yet, in the end, in the case of every \"genius\" who believes in his "
1439 "own divinity the poison shows itself to the same degree as his \"genius\" grows "
1440 "old: one may recall, for example, the case of Napoleon, whose nature certainly "
1441 "grew into the mighty unity that sets him apart from all men of modern times "
1442 "precisely through his belief in himself and his star and through the contempt "
1443 "for men that flowed from it; until in the end, however, this same belief went "
1444 "over into an almost insane fatalism, robbed him of his acuteness and swiftness "
1445 "of perception, and became the cause of his destruction.";