oops

resource/specialize/js-impl.js

@@ -0,0 +1,103 @@
+var resourceType = MACHINE.modules['whalesong/resource/structs.rkt'].getNamespace()['struct:resource'];
+
+var makeClosure = plt.baselib.functions.makeClosure;
+var finalizeClosureCall = plt.baselib.functions.finalizeClosureCall;
+
+var checkResource = plt.baselib.check.makeCheckArgumentType(
+    resourceType.predicate,
+    "resource");
+
+var getResourcePath = function(r) { return resourceType.accessor(r, 0); };
+var getResourceKey = function(r) { return resourceType.accessor(r, 1); };
+
+var PAUSE = plt.runtime.PAUSE;
+
+
+
+
+var imageExtensions = { 'png' : true,
+                        'gif' : true,
+                        'jpeg' : true,
+                        'jpg' : true,
+                        'bmp' : true };
+
+var isImagePath = function(s) {
+    var extensionMatch = s.toLowerCase().match(/\.(\w+)$/);
+    if (extensionMatch !== null && imageExtensions[extensionMatch[1]])
+        return true;
+    return false;
+};
+
+
+
+// A lot of this comes from image/private/kernel.js
+var injectImageMethods = function(r, img) {
+    r.img = img;
+    r.getHeight = function() { return img.width; };
+    r.getWidth = function() { return img.height; };
+    r.getBaseline = function() { return img.height; };
+    r.updatePinhole = function() {
+        var aCopy = plt.baselib.clone(this);
+        aCopy.pinholeX = x;
+        aCopy.pinholeY = y;
+        return aCopy;
+    };
+    r.render = function(ctx, x, y) {
+        installHackToSupportAnimatedGifs(r);
+        ctx.drawImage(r.animationHackImg, x, y);
+    };
+    r.toDomNode = function() {
+        return img.cloneNode(true);
+    };
+};
+
+var installHackToSupportAnimatedGifs = function(r) {
+    if (r.animationHackImg) { return; }
+    r.animationHackImg = r.img.cloneNode(true);
+    document.body.appendChild(r.animationHackImg);
+    r.animationHackImg.width = 0;
+    r.animationHackImg.height = 0;
+};
+
+
+
+
+
+
+
+// If the resource is an image, decorate the value with the image properties.
+EXPORTS['specialize!'] = makeClosure(
+    'specialize!',
+    1,
+    function(MACHINE) {
+        var resource = checkResource(MACHINE, 'specialize!', 0);
+        var oldArgcount = MACHINE.argcount;
+        if (isImagePath(getResourceKey(resource).toString())) {
+            return PAUSE(
+                function(restart) {
+                    var rawImage = new Image();
+                    rawImage.onload = function() {
+                        delete(rawImage.onload);
+                        delete(rawImage.onerror);
+                        injectImageMethods(resource, rawImage);
+                        restart(function(MACHINE) {
+                            MACHINE.argcount = oldArgcount;
+                            return finalizeClosureCall(MACHINE, resource);
+                        });
+                    };
+                    rawImage.onerror = function(e) {
+                        delete(rawImage.onload);
+                        delete(rawImage.onerror);
+                        // on any kind of image-loading error, fail out and
+                        // just return the resource unchanged.
+                        restart(function(MACHINE) {
+                            MACHINE.argcount = oldArgcount;
+                            return finalizeClosureCall(MACHINE, resource);
+                        });
+                    }
+                    rawImage.src = getResourceKey(resource).toString();
+                });
+        } else {
+            return finalizeClosureCall(MACHINE, resource);
+        }
+    });