| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: wx/dcbuffer.h |
| 3 | // Purpose: wxBufferedDC class |
| 4 | // Author: Ron Lee <ron@debian.org> |
| 5 | // Modified by: Vadim Zeitlin (refactored, added bg preservation) |
| 6 | // Created: 16/03/02 |
| 7 | // Copyright: (c) Ron Lee |
| 8 | // Licence: wxWindows licence |
| 9 | ///////////////////////////////////////////////////////////////////////////// |
| 10 | |
| 11 | #ifndef _WX_DCBUFFER_H_ |
| 12 | #define _WX_DCBUFFER_H_ |
| 13 | |
| 14 | #include "wx/dcmemory.h" |
| 15 | #include "wx/dcclient.h" |
| 16 | #include "wx/window.h" |
| 17 | |
| 18 | // Split platforms into two groups - those which have well-working |
| 19 | // double-buffering by default, and those which do not. |
| 20 | #if defined(__WXMAC__) || defined(__WXGTK20__) || defined(__WXDFB__) |
| 21 | #define wxALWAYS_NATIVE_DOUBLE_BUFFER 1 |
| 22 | #else |
| 23 | #define wxALWAYS_NATIVE_DOUBLE_BUFFER 0 |
| 24 | #endif |
| 25 | |
| 26 | |
| 27 | // ---------------------------------------------------------------------------- |
| 28 | // Double buffering helper. |
| 29 | // ---------------------------------------------------------------------------- |
| 30 | |
| 31 | // Assumes the buffer bitmap covers the entire scrolled window, |
| 32 | // and prepares the window DC accordingly |
| 33 | #define wxBUFFER_VIRTUAL_AREA 0x01 |
| 34 | |
| 35 | // Assumes the buffer bitmap only covers the client area; |
| 36 | // does not prepare the window DC |
| 37 | #define wxBUFFER_CLIENT_AREA 0x02 |
| 38 | |
| 39 | // Set when not using specific buffer bitmap. Note that this |
| 40 | // is private style and not returned by GetStyle. |
| 41 | #define wxBUFFER_USES_SHARED_BUFFER 0x04 |
| 42 | |
| 43 | class WXDLLIMPEXP_CORE wxBufferedDC : public wxMemoryDC |
| 44 | { |
| 45 | public: |
| 46 | // Default ctor, must subsequently call Init for two stage construction. |
| 47 | wxBufferedDC() |
| 48 | : m_dc(NULL), |
| 49 | m_buffer(NULL), |
| 50 | m_style(0) |
| 51 | { |
| 52 | } |
| 53 | |
| 54 | // Construct a wxBufferedDC using a user supplied buffer. |
| 55 | wxBufferedDC(wxDC *dc, |
| 56 | wxBitmap& buffer = wxNullBitmap, |
| 57 | int style = wxBUFFER_CLIENT_AREA) |
| 58 | : m_dc(NULL), m_buffer(NULL) |
| 59 | { |
| 60 | Init(dc, buffer, style); |
| 61 | } |
| 62 | |
| 63 | // Construct a wxBufferedDC with an internal buffer of 'area' |
| 64 | // (where area is usually something like the size of the window |
| 65 | // being buffered) |
| 66 | wxBufferedDC(wxDC *dc, const wxSize& area, int style = wxBUFFER_CLIENT_AREA) |
| 67 | : m_dc(NULL), m_buffer(NULL) |
| 68 | { |
| 69 | Init(dc, area, style); |
| 70 | } |
| 71 | |
| 72 | // The usually desired action in the dtor is to blit the buffer. |
| 73 | virtual ~wxBufferedDC() |
| 74 | { |
| 75 | if ( m_dc ) |
| 76 | UnMask(); |
| 77 | } |
| 78 | |
| 79 | // These reimplement the actions of the ctors for two stage creation |
| 80 | void Init(wxDC *dc, |
| 81 | wxBitmap& buffer = wxNullBitmap, |
| 82 | int style = wxBUFFER_CLIENT_AREA) |
| 83 | { |
| 84 | InitCommon(dc, style); |
| 85 | |
| 86 | m_buffer = &buffer; |
| 87 | |
| 88 | UseBuffer(); |
| 89 | } |
| 90 | |
| 91 | void Init(wxDC *dc, const wxSize &area, int style = wxBUFFER_CLIENT_AREA) |
| 92 | { |
| 93 | InitCommon(dc, style); |
| 94 | |
| 95 | UseBuffer(area.x, area.y); |
| 96 | } |
| 97 | |
| 98 | // Blits the buffer to the dc, and detaches the dc from the buffer (so it |
| 99 | // can be effectively used once only). |
| 100 | // |
| 101 | // Usually called in the dtor or by the dtor of derived classes if the |
| 102 | // BufferedDC must blit before the derived class (which may own the dc it's |
| 103 | // blitting to) is destroyed. |
| 104 | void UnMask(); |
| 105 | |
| 106 | // Set and get the style |
| 107 | void SetStyle(int style) { m_style = style; } |
| 108 | int GetStyle() const { return m_style & ~wxBUFFER_USES_SHARED_BUFFER; } |
| 109 | |
| 110 | private: |
| 111 | // common part of Init()s |
| 112 | void InitCommon(wxDC *dc, int style) |
| 113 | { |
| 114 | wxASSERT_MSG( !m_dc, wxT("wxBufferedDC already initialised") ); |
| 115 | |
| 116 | m_dc = dc; |
| 117 | m_style = style; |
| 118 | } |
| 119 | |
| 120 | // check that the bitmap is valid and use it |
| 121 | void UseBuffer(wxCoord w = -1, wxCoord h = -1); |
| 122 | |
| 123 | // the underlying DC to which we copy everything drawn on this one in |
| 124 | // UnMask() |
| 125 | // |
| 126 | // NB: Without the existence of a wxNullDC, this must be a pointer, else it |
| 127 | // could probably be a reference. |
| 128 | wxDC *m_dc; |
| 129 | |
| 130 | // the buffer (selected in this DC), initially invalid |
| 131 | wxBitmap *m_buffer; |
| 132 | |
| 133 | // the buffering style |
| 134 | int m_style; |
| 135 | |
| 136 | wxSize m_area; |
| 137 | |
| 138 | DECLARE_DYNAMIC_CLASS(wxBufferedDC) |
| 139 | wxDECLARE_NO_COPY_CLASS(wxBufferedDC); |
| 140 | }; |
| 141 | |
| 142 | |
| 143 | // ---------------------------------------------------------------------------- |
| 144 | // Double buffered PaintDC. |
| 145 | // ---------------------------------------------------------------------------- |
| 146 | |
| 147 | // Creates a double buffered wxPaintDC, optionally allowing the |
| 148 | // user to specify their own buffer to use. |
| 149 | class WXDLLIMPEXP_CORE wxBufferedPaintDC : public wxBufferedDC |
| 150 | { |
| 151 | public: |
| 152 | // If no bitmap is supplied by the user, a temporary one will be created. |
| 153 | wxBufferedPaintDC(wxWindow *window, wxBitmap& buffer, int style = wxBUFFER_CLIENT_AREA) |
| 154 | : m_paintdc(window) |
| 155 | { |
| 156 | // If we're buffering the virtual window, scale the paint DC as well |
| 157 | if (style & wxBUFFER_VIRTUAL_AREA) |
| 158 | window->PrepareDC( m_paintdc ); |
| 159 | |
| 160 | if( buffer.IsOk() ) |
| 161 | Init(&m_paintdc, buffer, style); |
| 162 | else |
| 163 | Init(&m_paintdc, GetBufferedSize(window, style), style); |
| 164 | } |
| 165 | |
| 166 | // If no bitmap is supplied by the user, a temporary one will be created. |
| 167 | wxBufferedPaintDC(wxWindow *window, int style = wxBUFFER_CLIENT_AREA) |
| 168 | : m_paintdc(window) |
| 169 | { |
| 170 | // If we're using the virtual window, scale the paint DC as well |
| 171 | if (style & wxBUFFER_VIRTUAL_AREA) |
| 172 | window->PrepareDC( m_paintdc ); |
| 173 | |
| 174 | Init(&m_paintdc, GetBufferedSize(window, style), style); |
| 175 | } |
| 176 | |
| 177 | // default copy ctor ok. |
| 178 | |
| 179 | virtual ~wxBufferedPaintDC() |
| 180 | { |
| 181 | // We must UnMask here, else by the time the base class |
| 182 | // does it, the PaintDC will have already been destroyed. |
| 183 | UnMask(); |
| 184 | } |
| 185 | |
| 186 | protected: |
| 187 | // return the size needed by the buffer: this depends on whether we're |
| 188 | // buffering just the currently shown part or the total (scrolled) window |
| 189 | static wxSize GetBufferedSize(wxWindow *window, int style) |
| 190 | { |
| 191 | return style & wxBUFFER_VIRTUAL_AREA ? window->GetVirtualSize() |
| 192 | : window->GetClientSize(); |
| 193 | } |
| 194 | |
| 195 | private: |
| 196 | wxPaintDC m_paintdc; |
| 197 | |
| 198 | DECLARE_ABSTRACT_CLASS(wxBufferedPaintDC) |
| 199 | wxDECLARE_NO_COPY_CLASS(wxBufferedPaintDC); |
| 200 | }; |
| 201 | |
| 202 | |
| 203 | |
| 204 | // |
| 205 | // wxAutoBufferedPaintDC is a wxPaintDC in toolkits which have double- |
| 206 | // buffering by default. Otherwise it is a wxBufferedPaintDC. Thus, |
| 207 | // you can only expect it work with a simple constructor that |
| 208 | // accepts single wxWindow* argument. |
| 209 | // |
| 210 | #if wxALWAYS_NATIVE_DOUBLE_BUFFER |
| 211 | #define wxAutoBufferedPaintDCBase wxPaintDC |
| 212 | #else |
| 213 | #define wxAutoBufferedPaintDCBase wxBufferedPaintDC |
| 214 | #endif |
| 215 | |
| 216 | class WXDLLIMPEXP_CORE wxAutoBufferedPaintDC : public wxAutoBufferedPaintDCBase |
| 217 | { |
| 218 | public: |
| 219 | |
| 220 | wxAutoBufferedPaintDC(wxWindow* win) |
| 221 | : wxAutoBufferedPaintDCBase(win) |
| 222 | { |
| 223 | wxASSERT_MSG( win->GetBackgroundStyle() == wxBG_STYLE_PAINT, |
| 224 | "You need to call SetBackgroundStyle(wxBG_STYLE_PAINT) in ctor, " |
| 225 | "and also, if needed, paint the background in wxEVT_PAINT handler." |
| 226 | ); |
| 227 | } |
| 228 | |
| 229 | virtual ~wxAutoBufferedPaintDC() { } |
| 230 | |
| 231 | private: |
| 232 | wxDECLARE_NO_COPY_CLASS(wxAutoBufferedPaintDC); |
| 233 | }; |
| 234 | |
| 235 | |
| 236 | |
| 237 | // Check if the window is natively double buffered and will return a wxPaintDC |
| 238 | // if it is, a wxBufferedPaintDC otherwise. It is the caller's responsibility |
| 239 | // to delete the wxDC pointer when finished with it. |
| 240 | inline wxDC* wxAutoBufferedPaintDCFactory(wxWindow* window) |
| 241 | { |
| 242 | if ( window->IsDoubleBuffered() ) |
| 243 | return new wxPaintDC(window); |
| 244 | else |
| 245 | return new wxBufferedPaintDC(window); |
| 246 | } |
| 247 | |
| 248 | #endif // _WX_DCBUFFER_H_ |