Suppose I have an image "tall.png" which is too tall for the block that it is being placed in. I would like the image to automatically scale down to fit into the parent block.
A simple example of what I mean:
<fo:block-container height="10cm" width="10cm" border="solid 0.5px black">
<fo:block>
<fo:external-graphic src="tall.png"
content-width="scale-down-to-fit" content-height="scale-down-to-fit"
width="100%" height="100%"/>
</fo:block>
</fo:block-container>
The above code doesn't seem to work. The resulting PDF shows the image spilling out of the block-container. On the other hand, if I do this...
<fo:block-container height="10cm" width="10cm" border="solid 0.5px black">
<fo:block>
<fo:external-graphic src="tall.png"
content-width="scale-down-to-fit" content-height="scale-down-to-fit"
width="10cm" height="10cm"/>
</fo:block>
</fo:block-container>
That seems to work. This surprises me since the height property should refer to the height of the containing block when you use percentages (http://www.w3schools.com/xslfo/prop_height.asp). That makes me think that using 100% and using 10cm in my example should be exactly the same, but they don't produce the same result.
For the actual problem that I am trying to solve, I can't hardcode the width and height for the external-graphic. I need it to just stay within the height/width of its parent block, whatever that might be. Any idea how to accomplish that?