From ebce9281499a18b5ac4ae3b5e9cdc7b5f06ecbb0 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 11 Sep 2015 13:11:49 +0200
Subject: [PATCH 1/3] Extract the conversion from `canvas` to `image` into a
helper function in `PDFThumbnailView`
*Follow-up to PR 6299.*
This patch reduces unnecessary code duplication for the `canvas` to `image` conversion. It also does a bit of re-ordering (and adds new lines) in `_getPageDrawContext`, since that function currently is a bit hard to read.
---
web/pdf_thumbnail_view.js | 47 ++++++++++++++++++++++++++-------------
1 file changed, 32 insertions(+), 15 deletions(-)
diff --git a/web/pdf_thumbnail_view.js b/web/pdf_thumbnail_view.js
index 0d4752f2d..71488c114 100644
--- a/web/pdf_thumbnail_view.js
+++ b/web/pdf_thumbnail_view.js
@@ -186,24 +186,48 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
var ctx = canvas.getContext('2d');
var outputScale = getOutputScale(ctx);
+
canvas.width = (this.canvasWidth * outputScale.sx) | 0;
canvas.height = (this.canvasHeight * outputScale.sy) | 0;
canvas.style.width = this.canvasWidth + 'px';
canvas.style.height = this.canvasHeight + 'px';
+
if (!noCtxScale && outputScale.scaled) {
ctx.scale(outputScale.sx, outputScale.sy);
}
- this.image = document.createElement('img');
- this.image.id = this.renderingId;
- this.image.style.height = canvas.style.height;
- this.image.style.width = canvas.style.width;
- this.image.className = 'thumbnailImage';
- this.image.setAttribute('aria-label', mozL10n.get('thumb_page_canvas',
+
+ var image = document.createElement('img');
+ image.id = this.renderingId;
+
+ image.className = 'thumbnailImage';
+ image.setAttribute('aria-label', mozL10n.get('thumb_page_canvas',
{ page: this.id }, 'Thumbnail of Page {{page}}'));
+
+ image.style.width = canvas.style.width;
+ image.style.height = canvas.style.height;
+
+ this.image = image;
this.ring.appendChild(this.image);
+
return ctx;
},
+ /**
+ * @private
+ */
+ _convertCanvasToImage: function PDFThumbnailView_convertCanvasToImage() {
+ if (!this.canvas) {
+ return;
+ }
+ this.image.src = this.canvas.toDataURL();
+
+ // Zeroing the width and height causes Firefox to release graphics
+ // resources immediately, which can greatly reduce memory consumption.
+ this.canvas.width = 0;
+ this.canvas.height = 0;
+ delete this.canvas;
+ },
+
draw: function PDFThumbnailView_draw() {
if (this.renderingState !== RenderingStates.INITIAL) {
console.error('Must be in new state before drawing');
@@ -232,12 +256,8 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
rejectRenderPromise(error);
return;
}
-
- self.image.src = self.canvas.toDataURL();
- self.canvas.width = 0;
- self.canvas.height = 0;
- delete self.canvas;
self.renderingState = RenderingStates.FINISHED;
+ self._convertCanvasToImage();
if (!error) {
resolveRenderPromise(undefined);
@@ -319,10 +339,7 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
}
ctx.drawImage(reducedImage, 0, 0, reducedWidth, reducedHeight,
0, 0, canvas.width, canvas.height);
- this.image.src = canvas.toDataURL();
- this.canvas.width = 0;
- this.canvas.height = 0;
- delete this.canvas;
+ this._convertCanvasToImage();
}
};
From 555c7925a0da9606f70c8f97c23d041d686e53ae Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 11 Sep 2015 13:18:35 +0200
Subject: [PATCH 2/3] Prevent `setImage` from failing to display small
thumbnails, by adding a missing `canvas` to `image` conversion
*Follow-up to PR 6299.*
---
web/pdf_thumbnail_view.js | 1 +
1 file changed, 1 insertion(+)
diff --git a/web/pdf_thumbnail_view.js b/web/pdf_thumbnail_view.js
index 71488c114..71f52aee6 100644
--- a/web/pdf_thumbnail_view.js
+++ b/web/pdf_thumbnail_view.js
@@ -315,6 +315,7 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
if (img.width <= 2 * canvas.width) {
ctx.drawImage(img, 0, 0, img.width, img.height,
0, 0, canvas.width, canvas.height);
+ this._convertCanvasToImage();
return;
}
// drawImage does an awful job of rescaling the image, doing it gradually.
From d7a90d83de4fed4c5cbebe870c9ecf98f5769660 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 11 Sep 2015 13:42:10 +0200
Subject: [PATCH 3/3] Delete, and clear, the `image` in
`PDFThumbnailView_reset`
*Follow-up to PR 6299.*
---
web/pdf_thumbnail_view.js | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/web/pdf_thumbnail_view.js b/web/pdf_thumbnail_view.js
index 71f52aee6..b8c54fe4f 100644
--- a/web/pdf_thumbnail_view.js
+++ b/web/pdf_thumbnail_view.js
@@ -160,6 +160,10 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
this.canvas.height = 0;
delete this.canvas;
}
+ if (this.image) {
+ this.image.removeAttribute('src');
+ delete this.image;
+ }
},
update: function PDFThumbnailView_update(rotation) {