3c4f71cc3d
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@52634 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
70 lines
2.4 KiB
Objective-C
70 lines
2.4 KiB
Objective-C
/////////////////////////////////////////////////////////////////////////////
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// Name: dcmemory.h
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// Purpose: interface of wxMemoryDC
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// Author: wxWidgets team
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// RCS-ID: $Id$
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// Licence: wxWindows license
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/////////////////////////////////////////////////////////////////////////////
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/**
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@class wxMemoryDC
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@wxheader{dcmemory.h}
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A memory device context provides a means to draw graphics onto a bitmap. When
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drawing in to a mono-bitmap, using @c wxWHITE, @c wxWHITE_PEN and
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@c wxWHITE_BRUSH
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will draw the background colour (i.e. 0) whereas all other colours will draw the
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foreground colour (i.e. 1).
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@library{wxcore}
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@category{dc}
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@see wxBitmap, wxDC
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*/
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class wxMemoryDC : public wxDC
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{
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public:
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//@{
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/**
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Constructs a new memory device context and calls SelectObject()
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with the given bitmap.
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Use the wxDC::IsOk member to test whether the constructor was successful
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in creating a usable device context.
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*/
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wxMemoryDC();
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wxMemoryDC(wxBitmap& bitmap);
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//@}
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/**
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Works exactly like SelectObjectAsSource() but
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this is the function you should use when you select a bitmap because you want
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to modify
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it, e.g. drawing on this DC.
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Using SelectObjectAsSource() when modifying
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the bitmap may incurr some problems related to wxBitmap being a reference
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counted object
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(see @ref overview_trefcount "reference counting overview").
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Also, before using the updated bitmap data, make sure to select it out of
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context first
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(for example by selecting wxNullBitmap into the device context).
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@see wxDC::DrawBitmap
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*/
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void SelectObject(wxBitmap& bitmap);
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/**
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Selects the given bitmap into the device context, to use as the memory
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bitmap. Selecting the bitmap into a memory DC allows you to draw into
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the DC (and therefore the bitmap) and also to use wxDC::Blit to copy
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the bitmap to a window. For this purpose, you may find wxDC::DrawIcon
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easier to use instead.
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If the argument is wxNullBitmap (or some other uninitialised wxBitmap) the
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current bitmap is
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selected out of the device context, and the original bitmap restored, allowing
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the current bitmap to
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be destroyed safely.
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*/
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void SelectObjectAsSource(const wxBitmap& bitmap);
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};
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