511951 - Cannot drag scroll bars on frames going from visibility:hidden to visibility:visible

Status: RESOLVED FIXED

(Core :: Layout, defect, P1)

Description

[Sylvain Pasche]

Attachment: testcase

I noticed this issue on a meta-search web application which uses frames to show search engines results.

I set a breakpoint in nsViewManager::GrabMouseEvents and noticed that IsEffectivelyVisible() is returning false when you try to drag the scroll bar in the attached testcase.

Apparently, when setting the the frame visibility to "visible", some views are still in the nsViewVisibility_kHide state.

Here's the view dump when loading the testcase with the frame having a visibility: hidden style and before setting it to visible:
z=0 pos={0,0,35748,20952}) {0,0,35748,20952} z=0 vi
s=1 clientData=097C63C0 <
  05688820 {0,0,35748,20952} z=0 vis=1 clientData=097C68E8 <
    0507FAD8 {0,0,35748,20952} z=0 vis=1 clientData=00000000 <
      05274098 {0,0,35748,20952} z=0 vis=1 clientData=097C67D0 <
        053539D0 {480,3054,18216,9216} z=0 vis=0 clientData=09764CA0 <
          07DEEA30 {108,108,18000,9000} z=0 vis=0 clientData=00000000 <
            07E64B80 {0,0,17982,9018} z=0 vis=1 clientData=097A1388 <
              090E7E00 {0,0,17982,9018} z=0 vis=1 clientData=097A18B0 <
                03DAF610 {0,0,16956,7992} z=0 vis=1 clientData=00000000 <
                  09101D88 {0,0,60480,60960} z=0 vis=1 clientData=097A1798 <
                  >
                >
                03ED2340 {16956,1026,1026,5940} z=0 vis=1 clientData=09810208 <
                >
                056D3E68 {1026,7992,14904,1026} z=0 vis=1 clientData=0980F4D8 <
                >
              >
            >

After setting the frame to visibility: hidden, we have:
z=0 pos={0,0,35748,20952}) {0,0,35748,20952} z=0 vi
s=1 clientData=097C63C0 <
  05688820 {0,0,35748,20952} z=0 vis=1 clientData=097C68E8 <
    0507FAD8 {0,0,35748,20952} z=0 vis=1 clientData=00000000 <
      05274098 {0,0,35748,20952} z=0 vis=1 clientData=097C67D0 <
        053539D0 {480,3054,18216,9216} z=0 vis=1 clientData=09764CA0 <
          07DEEA30 {108,108,18000,9000} z=0 vis=0 clientData=00000000 <
            07E64B80 {0,0,17982,9018} z=0 vis=1 clientData=097A1388 <
              090E7E00 {0,0,17982,9018} z=0 vis=1 clientData=097A18B0 <
                03DAF610 {0,0,16956,7992} z=0 vis=1 clientData=00000000 <
                  09101D88 {0,0,60480,60960} z=0 vis=1 clientData=097A1798 <
                  >
                >
                03ED2340 {16956,1026,1026,5940} z=0 vis=1 clientData=09810208 <
                >
                056D3E68 {1026,7992,14904,1026} z=0 vis=1 clientData=0980F4D8 <
                >
              >
            >

You can notice that one view has vis=0. This causes IsEffectivelyVisible() to return false.

On the other hand, if you load the testcase with the frame having a visibility: visible style:
z=0 pos={0,0,35748,20952}) {0,0,35748,20952} z=0 vi
s=1 clientData=097C8940 <
  0563E698 {0,0,35748,20952} z=0 vis=1 clientData=097C8E68 <
    090B9CD8 {0,0,35748,20952} z=0 vis=1 clientData=00000000 <
      03EEB618 {0,0,35748,20952} z=0 vis=1 clientData=097C8D50 <
        080429D8 {480,3054,18216,9216} z=0 vis=1 clientData=09766148 <
          05688820 {108,108,18000,9000} z=0 vis=0 clientData=00000000 <
            057C0508 {0,0,17982,9018} z=0 vis=1 clientData=0978F440 <
              05713A28 {0,0,17982,9018} z=0 vis=1 clientData=0978F968 <
                03EF7C58 {0,0,16956,7992} z=0 vis=1 clientData=00000000 <
                  08F95CE8 {0,0,60480,60960} z=0 vis=1 clientData=0978F850 <
                  >
                >
                081DAFF8 {16956,1026,1026,5940} z=0 vis=1 clientData=09792A40 <
                >
                056DF208 {1026,7992,14904,1026} z=0 vis=1 clientData=09791D10 <
                >
              >

In this case, all views are visible and IsEffectivelyVisible() is returning true which makes the scroll bar works as expected.

Comment 1

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: fix [Checkin: Comment 3 & 6]

The problem is that we're making the inner view hidden if the frame's view is hidden, but after the deck widget removal patch, changing the frame's view to visible does not unhide the inner view.

The solution is to just not hide the inner view. That's not needed since the hidden outer view makes all the descendants behave as effectively hidden.

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 396399 [details] [diff] [review]
fix
[Checkin: Comment 3 & 6]

r=dbaron

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

http://hg.mozilla.org/mozilla-central/rev/e2af1f122512

Comment 4

[Rob Campbell [:rc] (:robcee)]

do we need additional approval to land this on 1.9.2? I just ran a quick test on a local build of 1.9.2 and this fixes the two dependent bugs.

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

No, we don't.

Comment 6

[Serge Gautherie (:sgautherie)]

Comment on attachment 396399 [details] [diff] [review]
fix
[Checkin: Comment 3 & 6]


http://hg.mozilla.org/releases/mozilla-1.9.2/rev/356ca1cc0a60