70 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			HTML
		
	
	
	
			
		
		
	
	
			70 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			HTML
		
	
	
	
<HTML><HEAD><TITLE>STk procedure - make-image manual page</TITLE></HEAD>
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<BR>
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<BODY bgcolor = #c3ffc3>
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<H2><IMG ALIGN=BOTTOM SRC="./Img/ManPageGreen.gif"> create-image, find-image, change-image, free-image </H2>
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<I>an easier way to manipulate Tk images
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</I><P><IMG ALIGN=TOP SRC="./Img/line-red.gif">
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<H3><A NAME="M2">PACKAGE</A></H3>
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Tk
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<H3><A NAME="M3">SYNOPSIS</A></H3>
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(<B>make-image</B> key <I>create image ?options?</I>)<BR>
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(<B>find-image</B> key)<BR>
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(<B>change-image</B> key  <I>create image options</I>)<BR>
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(<B>free-image</B> key)<BR>
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<H3><A NAME="M4">DESCRIPTION</A></H3>
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<B>make-image</B> is a STk procedure which simplifies Tk images
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creation by providing a homogeneous way to create an image,
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independently of its coding format.  The first argument of
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<B>make-image</B> is a string which identifies the image; if an image
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with this key has been already loaded in memory, it will not be loaded
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again and <B>make-image</B> will return it. If no option is given,
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the identifying image key is taken as a file name (the file is searched 
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using the variable <B>*image-path*</B>, which must contain a set of 
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prefix pathnames to prepend to the given filename).
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If options are passed to the <B>make-image</B>  procedure they must follow
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the convention of the options passed in <B><A HREF=../Help/./image.n.html>image create</A></B> just after the
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image format. If the image cannot be created, this procedure returns <B>#f</B>.
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<P>
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Hereafter is a simple usage of this procedure:
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<P>
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<PRE>(require "image")
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(require "pixmap")
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(define img1 (make-image "a pixmap" :file "exit.xpm"))
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(define img2 (make-image "a bitmap" :file "default.xbm"))
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(define img3 (make-image "a pixmap"))
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(define img4 (make-image "x.xpm"))</PRE>
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In this case, <I>img3</I> is identical to <I>img1</I> since they use the same key.
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<I>Img4</I> is the image associated to the file "x.xpm" found according to 
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the  *image-path* varaiable.
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<P>
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<B>find-image</B> returns the image associated to the given <I>key</I> or 
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<B>#f</B> if this image has not been loaded yet.
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<P>
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<B>change-image</B> changes the content of an image previously created with
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<B>make-image</B>. Options are the identical to <B>make-image</B>
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options.
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<P>
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Example:
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<PRE>(button '.b1 :image img1)
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(button '.b2 :image img2)
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(button '.b3 :image img1) ; .b3 content is identical to .b1
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(pack .b1 .b2 .b3)
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(change-image "a pixmap" :file "default.xbm")</PRE>
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After the execution of <B>change-image</B>, both <I>.b1</I> and <I>.b3</I>
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graphical contents are changed.
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<P>
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<B>delete-image</B> removes the image with the given key of the cache.
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The memory used by this image is returned to the system. See the 
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discussion about how this image is displayed in <B><A HREF=../Help/./image.n.html>image delete</A></B>.
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<H3><A NAME="M5">SEE ALSO</A></H3>
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<B><A HREF="./bitmap.n.html">bitmap</A></B>, <B><A HREF="./image.n.html">image</A></B>, <B><A HREF="./jpeg.n.html">jpeg</A></B>, <B><A HREF="./photo.n.html">photo</A></B>, <B><A HREF="./pixmap.n.html">pixmap</A></B>
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<P><IMG ALIGN=TOP SRC="./Img/line-red.gif"><P>
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<A HREF=./STk-hlp.html><IMG ALIGN=BOTTOM SRC="./Img/RefBookGreen.gif"> Back to the <B>STk</B> main page</A>
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</BODY></HTML>
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