With some logging, here's what I see on a tarako, when going to the homescreen and launching the same app again: E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:145 in aw__showFrame: _showFrame E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:145 in aw__showFrame: _showFrame I/Gecko ( 6558): Taking a screenshot: maxWidth=320, maxHeight=460, domRequestID=req_0. E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:536 in aw_getScreenshot: getScreenshot E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:536 in aw_getScreenshot: getScreenshot I/Gecko ( 6558): Taking a screenshot: maxWidth=320, maxHeight=460, domRequestID=req_1. I/Gecko ( 6558): Screenshoot took in 326 ms. blob size is 21029 I/Gecko ( 6558): Screenshoot took in 249 ms. blob size is 21029 I/Gecko ( 6558): Taking a screenshot: maxWidth=1, maxHeight=1, domRequestID=req_2. E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:357 in onTWFRepaint: tryWaitForFullRepaint E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:372 in onTWFRepaint: getScreenshot 1x1 E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:145 in aw__showFrame: _showFrame E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:357 in onTWFRepaint: tryWaitForFullRepaint E/GeckoConsole( 6511): Content JS LOG at app://system.gaiamobile.org/js/window.js:372 in onTWFRepaint: getScreenshot 1x1 I/Gecko ( 6558): Screenshoot took in 78 ms. blob size is 629 I/Gecko ( 6558): Taking a screenshot: maxWidth=1, maxHeight=1, domRequestID=req_3. I/Gecko ( 6558): Screenshoot took in 27 ms. blob size is 629 There are at least 2 issues: - we still take screenshots when leaving the app, even if we will never use them. To make sure we have a good one, we take 2. - the 1x1 screenshot is a hack to force a repaint of the frame before displaying it if I recall correctly. Here also, we take too of them. Alive, we should at least fix the useless calls to getScreenshot for tarako. I'm not sure what to do in 2.0 and later to have a way to turn that off per device though.

Maybe we can make a pref or a template for it or something? just noting bug 980829 is asking for a specific set of apps for Tarako engineering builds.

Consecutive two get-screenshot is fixed at https://bugzilla.mozilla.org/show_bug.cgi?id=1007574. For tarako since we don't take screenshot and user may not care about UX, we could return early on ensureFullRepaint.

1.3t only of course.

pushed on 1.3t: 303e375a1b4c721984dcb68dfca24d6f50c291f2

Alive, do we have the same issue in 1.4 window manager and need to be fixed too?

(In reply to Tim Guan-tin Chien [:timdream] (MoCo-TPE) (please ni?) from comment #5) > Alive, do we have the same issue in 1.4 window manager and need to be fixed > too? What is the "issue"? We don't have v1.4d yet (do we?) so we cannot turn all screenshot off for 1.4 branch.

We are indeed still using screenshots for cards view etc for 1.4, however I would like to know if the extra 1x1 screenshots need a fix on the new window management.

(In reply to Tim Guan-tin Chien [:timdream] (MoCo-TPE) (please ni?) from comment #7) > We are indeed still using screenshots for cards view etc for 1.4, however I > would like to know if the extra 1x1 screenshots need a fix on the new window > management. I don't know if we could patch 1.4, but what should be done is uplift https://bugzilla.mozilla.org/show_bug.cgi?id=1007574.