Adding handlers to zoom in/out on scrollwheel event.

Questions:
- Is deltaY the correct field in which to store this event value?
- Is the 'wheel' addEventListener hook broken in the first place? Doesn't work for me on OSX, but might be working in Windows/Linux and don't know if this change would break it for those.
- It is necessary to cancel event bubbling for the onmousewheel event?
Review URL: http://codereview.chromium.org/2456004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49305 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 20 insertions, 4 deletions

diff --git a/o3d/samples/o3d-webgl-samples/pool.html b/o3d/samples/o3d-webgl-samples/pool.html
index cabe6d0..14eca54 100644
--- a/o3d/samples/o3d-webgl-samples/pool.html
+++ b/o3d/samples/o3d-webgl-samples/pool.html
@@ -894,6 +894,8 @@ function registerEventCallbacks() {
   o3djs.event.addEventListener(g_o3dElement, 'keypress', keyPressed);
   o3djs.event.addEventListener(g_o3dElement, 'keyup', keyUp);
   o3djs.event.addEventListener(g_o3dElement, 'keydown', keyDown);
+
+  o3djs.event.addEventListener(g_o3dElement, 'wheel', scrollWheel);
 }
 
 
@@ -1884,6 +1886,22 @@ function keyDown(event) {
   }
 }
 
+function zoomIn() {
+  g_cameraInfo.targetPosition.radius *= 0.9;
+}
+
+function zoomOut() {
+  g_cameraInfo.targetPosition.radius /= 0.9;
+}
+
+function scrollWheel(event) {
+  if (event.deltaY > 0) {
+    zoomIn();
+  } else {
+    zoomOut();
+  }
+}
+
 function keyPressed(event) {
   var keyChar = String.fromCharCode(o3djs.event.getEventKeyChar(event));
   keyChar = keyChar.toLowerCase();
@@ -1943,12 +1961,12 @@ function keyPressed(event) {
 
     case '=':
     case '+':
-      g_cameraInfo.targetPosition.radius *= 0.9;
+      zoomIn();
       break;
 
     case '-':
     case '_':
-      g_cameraInfo.targetPosition.radius /= 0.9;
+      zoomOut();
       break;
 
     case ' ':
diff --git a/o3d/samples/o3d-webgl-samples/texturesamplers.html b/o3d/samples/o3d-webgl-samples/texturesamplers.html
index 13ef9c9..13fec25 100644
--- a/o3d/samples/o3d-webgl-samples/texturesamplers.html
+++ b/o3d/samples/o3d-webgl-samples/texturesamplers.html
@@ -74,8 +74,6 @@ var g_finished = false;  // for selenium testing
 function scrollMe(e) {
   g_eye = g_math.mulScalarVector((e.deltaY < 0 ? 11 : 13) / 12, g_eye);
   g_viewInfo.drawContext.view = g_math.matrix4.lookAt(g_eye, g_target, g_up);
-  // Prevents event from reaching up to the window, e.g. so page will not scroll
-  o3djs.event.cancel(e);
 }
 
 /**