shimmie2/ext/zoom/theme.php

<?php

class ZoomTheme extends Themelet {
	public function display_zoomer($page, $zoom_by_default) {
		$page->add_block(new Block(null, $this->make_zoomer($zoom_by_default)));
	}
	
	private function make_zoomer($zoom_by_default) {
		global $config;
		$default = $zoom_by_default ? "scale(img);" : "";
		return <<<EOD
<script type="text/javascript">
img = document.getElementById("main_image");

img.onclick = function() {scale(img);};

msg_div = document.createElement("div");
msg_div.id = "msg_div";
msg_div.appendChild(document.createTextNode("Note: Image has been scaled to fit the screen; click to enlarge"));
msg_div.style.display="none";

img.parentNode.insertBefore(msg_div, img);

orig_width = "";

function scale(img) {
	// element.clientWidth is not part of the JS standard :(
	if(img.style.width != "90%" && (img.clientWidth >= img.parentNode.clientWidth * 0.9)) {
		origwidth = img.style.width;
		img.style.width = "90%";
		msg_div.style.display = "block";
	}
	else {
		img.style.width = origwidth;
		msg_div.style.display = "none";
	}
}

$default
</script>
EOD;
	}
}
?>