Merge lp:~ahayzen/music-app/cardview-fix-number-columns-zero into lp:music-app/remix

[Andrew Hayzen]

* Fix to prevent the number of columns dropping to 0 causing unexpected behaviour

* Fix to prevent the number of columns dropping to 0 causing unexpected behaviour

Note this only affects desktop.

On trunk if you resize the cardview so that the width is smaller than the target width for 1 item (usually ~15GU for music) the number of columns can be evaluated to zero causing strange behaviour when the window is then expanded again (eg two layers of cards appearing in the first column).

TESTING:
1) Start the app and ensure you are on a tab with the cardview
2) Resize the window of the application so that the width is as small as possible
3) Resize the window so that it is back to its original width
4) Confirm no cards are overlapping

[Ubuntu Phone Apps Jenkins Bot (ubuntu-phone-apps-jenkins-bot)]

PASSED: Continuous integration, rev:748
http://91.189.93.70:8080/job/music-app-ci/1165/
Executed test runs:
    SUCCESS: http://91.189.93.70:8080/job/generic-mediumtests-vivid/338
        deb: http://91.189.93.70:8080/job/generic-mediumtests-vivid/338/artifact/work/output/*zip*/output.zip
    SUCCESS: http://91.189.93.70:8080/job/music-app-vivid-amd64-ci/17

Click here to trigger a rebuild:
http://91.189.93.70:8080/job/music-app-ci/1165/rebuild

review: Approve (continuous-integration)

[Victor Thompson (vthompson)]

LGTM! Nice catch! :)

review: Approve

=== modified file 'common/CardView.qml'
--- common/CardView.qml	2014-11-11 19:11:53 +0000
+++ common/CardView.qml	2014-11-23 03:55:15 +0000
@@ -67,7 +67,7 @@
             anchors {
                 fill: parent
             }
-            columns: parseInt(cardViewFlickable.width / itemWidth)
+            columns: parseInt(cardViewFlickable.width / itemWidth) || 1  // never drop to 0
             flickable: cardViewFlickable
         }
     }

=== modified file 'common/ColumnFlow.qml'
--- common/ColumnFlow.qml	2014-11-11 20:13:50 +0000
+++ common/ColumnFlow.qml	2014-11-23 03:55:15 +0000
@@ -42,8 +42,7 @@
     onColumnWidthChanged: {
         if (restoring) {
             return;
-        }
-        else if (columns != columnHeights.length && visible) {
+        } else if (columns != columnHeights.length && visible) {
             // number of columns has changed so rebuild the columns
             rebuildColumns()
         } else {  // column width has changed update visible items properties linked to columnWidth