From 54d02ada78ee4d99d69f61dd45a92afa6d3d061b Mon Sep 17 00:00:00 2001
From: Antoine Vandecreme <antoine.vandecreme@nist.gov>
Date: Fri, 18 Oct 2013 15:16:49 -0400
Subject: [PATCH] Replace viewport.getImageZoomRatio by conversion methods
between viewport zoom and image zoom
---
src/viewport.js | 36 +++++++++++++++++++++++++++++-------
test/units.js | 11 ++++++++---
2 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/src/viewport.js b/src/viewport.js
index 6fa8931f..12fbd956 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -916,19 +916,41 @@ $.Viewport.prototype = {
return viewerCoordinates.plus(
OpenSeadragon.getElementPosition( this.viewer.element ));
},
-
+
/**
- * Get the zoom ratio of the image. 1 means original image size, 0.5 half size...
+ * Convert a viewport zoom to an image zoom.
+ * Image zoom: ratio of the original image size to displayed image size.
+ * 1 means original image size, 0.5 half size...
+ * Viewport zoom: ratio of the displayed image's width to viewport's width.
+ * 1 means identical width, 2 means image's width is twice the viewport's width...
* @function
- * @param {Boolean} current If true gives the current zoom otherwise gives the
+ * @param {Number} viewportZoom The viewport zoom
* target zoom.
- * @returns {Number}
+ * @returns {Number} imageZoom The image zoom
*/
- getImageZoomRatio: function( current ) {
+ viewportToImageZoom: function( viewportZoom ) {
var imageWidth = this.viewer.source.dimensions.x;
var containerWidth = this.getContainerSize().x;
- var zoomToZoomLevelRatio = containerWidth / imageWidth;
- return this.getZoom( current ) * zoomToZoomLevelRatio;
+ var viewportToImageZoomRatio = containerWidth / imageWidth;
+ return viewportZoom * viewportToImageZoomRatio;
+ },
+
+ /**
+ * Convert an image zoom to a viewport zoom.
+ * Image zoom: ratio of the original image size to displayed image size.
+ * 1 means original image size, 0.5 half size...
+ * Viewport zoom: ratio of the displayed image's width to viewport's width.
+ * 1 means identical width, 2 means image's width is twice the viewport's width...
+ * @function
+ * @param {Number} imageZoom The image zoom
+ * target zoom.
+ * @returns {Number} viewportZoom The viewport zoom
+ */
+ imageToViewportZoom: function( imageZoom ) {
+ var imageWidth = this.viewer.source.dimensions.x;
+ var containerWidth = this.getContainerSize().x;
+ var viewportToImageZoomRatio = imageWidth / containerWidth;
+ return imageZoom * viewportToImageZoomRatio;
}
};
diff --git a/test/units.js b/test/units.js
index 1417b801..348835b3 100644
--- a/test/units.js
+++ b/test/units.js
@@ -91,9 +91,14 @@
function checkZoom() {
var currentImageWidth = getCurrentImageWidth();
- var expected = currentImageWidth / imageWidth;
- var actual = viewport.getImageZoomRatio(true);
- equal(actual, expected);
+ var expectedImageZoom = currentImageWidth / imageWidth;
+ var expectedViewportZoom = viewport.getZoom(true);
+ var actualImageZoom = viewport.viewportToImageZoom(
+ expectedViewportZoom);
+ equal(actualImageZoom, expectedImageZoom);
+
+ var actualViewportZoom = viewport.imageToViewportZoom(actualImageZoom);
+ equal(actualViewportZoom, expectedViewportZoom);
}
checkZoom();