hterm 1.31: a new zoom warning
* Re-implement zoom detection in terms of the currentScale property of svg
elements. This requires the svg element to be in the topmost document,
or at least not in the "about:blank" document that the scrollport creates
so it may not be perfect, but it's better than nothing.
Change-Id: I57fb9fea24e0c9743b5abac695213333e356f022
Reviewed-on: https://chromium-review.googlesource.com/188911
Reviewed-by: Marvelous Marius <mschilder@chromium.org>
Reviewed-by: Robert Ginda <rginda@chromium.org>
Tested-by: Robert Ginda <rginda@chromium.org>
diff --git a/hterm/doc/changelog.txt b/hterm/doc/changelog.txt
index 561cb26..911f7b7 100644
--- a/hterm/doc/changelog.txt
+++ b/hterm/doc/changelog.txt
@@ -1,3 +1,10 @@
+1.31, 2014-03-04, Add svg based zoom detection.
+
+* Re-implement zoom detection in terms of the currentScale property of svg
+ elements. This requires the svg element to be in the topmost document,
+ or at least not in the "about:blank" document that the scrollport creates
+ so it may not be perfect, but it's better than nothing.
+
1.30, 2014-03-04, Even better recursive "copy" fix.
* BUG=chromium:340699: Auto copy doesn't work.
diff --git a/hterm/js/hterm_scrollport.js b/hterm/js/hterm_scrollport.js
index 66ba767..f5b7dc2 100644
--- a/hterm/js/hterm_scrollport.js
+++ b/hterm/js/hterm_scrollport.js
@@ -366,6 +366,20 @@
this.scrollArea_.style.cssText = 'visibility: hidden';
this.screen_.appendChild(this.scrollArea_);
+ // This svg element is used to detect when the browser is zoomed. It must be
+ // placed in the outermost document for currentScale to be correct.
+ // TODO(rginda): This means that hterm nested in an iframe will not correctly
+ // detect browser zoom level. We should come up with a better solution.
+ this.svg_ = this.div_.ownerDocument.createElementNS(
+ 'http://www.w3.org/2000/svg', 'svg');
+ this.svg_.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
+ this.svg_.setAttribute('version', '1.1');
+ this.svg_.style.cssText = (
+ 'position: absolute;' +
+ 'top: 0;' +
+ 'left: 0;' +
+ 'visibility: hidden');
+
this.setSelectionEnabled(true);
this.resize();
};
@@ -616,16 +630,9 @@
this.rowNodes_.removeChild(this.ruler_);
- if ('width' in this.document_) {
- size.zoomFactor = this.document_.width / this.document_.body.clientWidth;
- } else {
- // Current versions of Chrome have removed document.width/height. We can
- // no longer depend on it to determine the zoom factor.
- // TODO(rginda): Remove this code once document.width/height are a distant
- // memory.
- size.zoomFactor = 1;
- }
-
+ this.div_.ownerDocument.body.appendChild(this.svg_);
+ size.zoomFactor = this.svg_.currentScale;
+ this.div_.ownerDocument.body.removeChild(this.svg_);
return size;
};
