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Docs: LCL/graphics. Revises content in TBitmap.LoadFromStream. Patch by Werner Pamler.

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(cherry picked from commit b97c0935e7)
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dsiders 2023-10-05 23:10:13 +01:00
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commit 5f0809334b
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docs/xml/lcl/graphics.xml
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@ -14833,37 +14833,29 @@ Loads image data for the bitmap from the specified stream.
<p>
<var>LoadFromStream</var> is an overridden method used to read data for the
bitmap image from the <var>TStream</var> instance specified in
<var>AStream</var>. <var>ASize</var> contains the number of bytes to read in
<var>AStream</var>. <var>ASize</var> contains the number of bytes to read in
the method.
</p>
<p>
LoadFromStream provides supported for loading image data from a resource
stream. When AStream is a TResourceStream instance, image headers present in
the stream are handled in the method. This allows resources created using
either the RT_BITMAP or the RT_RCDATA resource types to be handled. If both a
BMP file and BMP image header are found in the stream (RT_RCDATA), the
inherited method is called to load the image content. If the BMP file header is
omitted (RT_BITMAP), the header is created and populated with the endian-ness
for the platform and the size for the stream data. A temporary stream instance
which includes the constructed header is used to load the image content in the
inherited method.
</p>
<p>
If AStream is not a TResourceStream instance, the inherited method is called to
read the information in the stream using the specified size.
The inherited method has been adapted for reading from a TResourceStream
instance which can contain data as RT_BITMAP or RT_RCDATA resource types having
slightly different binary structures.
</p>
<p>
LoadFromStream is called when the ReadData method is executed (in the
TRasterImage ancestor).
TRasterImage ancestor) or when a TBitmap instance calls LoadFromResourceName or
LoadFromResourceID.
</p>
</descr>
<version>
Modified in LCL version 3.0 to provide support for loading image data from a
stream with content using either the RT_RCDATA or RT_BITMAP resource types.
resource stream containing either the RT_RCDATA or RT_BITMAP resource types.
</version>
<seealso>
<link id="TRasterImage.LoadFromStream"/>
<link id="TRasterImage.ReadData"/>
<link id="TGraphic.LoadFromResoureName"/>
<link id="TGraphic.LoadFromResoureID"/>
<link id="#lcl.lcltype.TBitmapFileHeader">TBitmapFileHeader</link>
<link id="#lcl.lcltype.TResourceType">TResourceType</link>
<link id="#lcl.lcltype.RT_BITMAP">RT_BITMAP</link>