# :stopdoc:
# This file is automatically generated by the WXRuby3 documentation 
# generator. Do not alter this file.
# :startdoc:


module Wx

  # A memory device context provides a means to draw graphics onto a bitmap.
  # When drawing in to a mono-bitmap, using {Wx::WHITE}, {Wx::WHITE_PEN} and {Wx::WHITE_BRUSH} will draw the background colour (i.e. 0) whereas all other colours will draw the foreground colour (i.e. 1).
  # A bitmap must be selected into the new memory DC before it may be used for anything. Typical usage is as follows:
  # 
  #   // Create a memory DC
  #   wxMemoryDC temp_dc;
  #   temp_dc.SelectObject(test_bitmap);
  #   
  #   // We can now draw into the memory DC...
  #   // Copy from this DC to another DC.
  #   old_dc.Blit(250, 50, BITMAP_WIDTH, BITMAP_HEIGHT, temp_dc, 0, 0);
  # 
  # Note that the memory DC must be deleted (or the bitmap selected out of it) before a bitmap can be reselected into another memory DC.
  # And, before performing any other operations on the bitmap data, the bitmap must be selected out of the memory DC:
  # 
  #   temp_dc.SelectObject(wxNullBitmap);
  # 
  # This happens automatically when {Wx::MemoryDC} object goes out of scope.
  # Note that the scaling factor of the bitmap determines the scaling factor used by this device context, so when using a memory device context as a back buffer for a window, you should typically create the bitmap using the same scale factor as used by the window, e.g. 
  # 
  #   void MyWindow::OnPaint(wxPaintEvent&)
  #   {
  #       wxBitmap bmp;
  #       bmp.CreateWithDIPSize(GetClientSize(), GetDPIScaleFactor());
  #       {
  #           wxMemoryDC memdc(bmp);
  #           ... use memdc to draw on the bitmap ...
  #       }
  #   
  #       wxPaintDC dc(this);
  #       dc.DrawBitmap(bmp, wxPoint(0, 0));
  #   }
  # 
  # === 
  # 
  # Category:  Device Contexts
  # @see Wx::Bitmap
  # @see  Wx::DC 
  # 
  # 
  class MemoryDC < DC
  
    # @overload initialize()
    #   Constructs a new memory device context.
    #   Use the {Wx::DC#is_ok} member to test whether the constructor was successful in creating a usable device context. Don't forget to select a bitmap into the DC before drawing on it.
    #   @return [MemoryDC]
    # @overload initialize(dc)
    #   Constructs a new memory device context having the same characteristics as the given existing device context.
    #   This constructor creates a memory device context compatible with dc in {Wx::MSW}, the argument is ignored in the other ports. If dc is NULL, a device context compatible with the screen is created, just as with the default constructor.
    #   @param dc [Wx::DC] 
    #   @return [MemoryDC]
    # @overload initialize(bitmap)
    #   Constructs a new memory device context and calls {Wx::MemoryDC#select_object} with the given bitmap.
    #   Use the {Wx::DC#is_ok} member to test whether the constructor was successful in creating a usable device context.
    #   @param bitmap [Wx::Bitmap] 
    #   @return [MemoryDC]
    def initialize(*args) end
    
    # Allow using this device context object to modify the given bitmap contents.
    # Note that if you need to only use the existing bitmap contents instead of modifying it, you should use {Wx::MemoryDC#select_object_as_source} instead.
    # Before using the updated bitmap data, make sure to select it out of context first either by selecting {Wx::NULL_BITMAP} into the device context or destroying the device context entirely.
    # If the bitmap is already selected in this device context, nothing is done. If it is selected in another context, the function asserts and drawing on the bitmap won't work correctly.
    # @param bitmap [Wx::Bitmap] 
    # @return [void]
    def select_object(bitmap) end
    
    # Selects the given bitmap into the device context, to use as the memory bitmap.
    # Selecting the bitmap as source into a memory DC allows you to copy its contents to another device context using {Wx::DC#blit}. Note that using {Wx::DC#draw_bitmap} or {Wx::DC#draw_icon} is a simpler way to do the same thing.
    # Modifying a bitmap selected only as a source may not work correctly and can notably modify the other bitmaps sharing the same data due to the use of reference counting (see Reference Counting).
    # 
    # If the argument is {Wx::NULL_BITMAP} (or some other uninitialised {Wx::Bitmap}) the current bitmap is selected out of the device context, allowing the current bitmap to be destroyed safely.
    # @param bitmap [Wx::Bitmap] 
    # @return [void]
    def select_object_as_source(bitmap) end
    
    # @overload get_selected_bitmap()
    #   Get the selected bitmap.
    #   @return [void]
    # @overload get_selected_bitmap()
    #   @return [Wx::Bitmap]
    def get_selected_bitmap(*args) end
    alias_method :selected_bitmap, :get_selected_bitmap
    
  end # MemoryDC
  

end