Tumbler: add positionViewAtIndex() function

This calls the respective PathView/ListView function (depending on
the value of wrap), and allows users to change the current index
without animations.

[ChangeLog][Controls][Tumbler] Added positionViewAtIndex() function
that calls the respective PathView/ListView function, depending on
the value of wrap. This allows changing currentIndex without
animations.

Task-number: QTBUG-66358
Change-Id: I7fe73bd3e53548ef41a165b68637d99f3171e02e
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

1 files changed, 64 insertions, 0 deletions

diff --git a/tests/auto/controls/data/tst_tumbler.qml b/tests/auto/controls/data/tst_tumbler.qml
index 058cbeca..d64f7c9c 100644
--- a/tests/auto/controls/data/tst_tumbler.qml
+++ b/tests/auto/controls/data/tst_tumbler.qml
@@ -107,6 +107,10 @@ TestCase {
         return Qt.point(tumblerXCenter(), yCenter);
     }
 
+    function itemTopLeftPos(visualItemIndex) {
+        return Qt.point(tumbler.leftPadding, tumbler.topPadding + (tumblerDelegateHeight * visualItemIndex));
+    }
+
     function checkItemSizes() {
         var contentChildren = tumbler.wrap ? tumblerView.children : tumblerView.contentItem.children;
         verify(contentChildren.length >= tumbler.count);
@@ -131,6 +135,21 @@ TestCase {
         return null;
     }
 
+    function findDelegateWithText(parent, text) {
+        for (var i = 0; i < parent.children.length; ++i) {
+            var child = parent.children[i];
+            if (child.hasOwnProperty("text") && child.text === text) {
+                return child;
+            }
+
+            var grandChild = findDelegateWithText(child, text);
+            if (grandChild)
+                return grandChild;
+        }
+
+        return null;
+    }
+
     property Component noAttachedPropertiesDelegate: Text {
         text: modelData
     }
@@ -1112,4 +1131,49 @@ TestCase {
         var label = row.label;
         compare(label.text, "2");
     }
+
+    function test_positionViewAtIndex_data() {
+        return [
+            // Should be 20, 21, ... but there is a documented limitation for this in positionViewAtIndex()'s docs.
+            { tag: "wrap=true, mode=Beginning", wrap: true, mode: Tumbler.Beginning, expectedVisibleIndices: [21, 22, 23, 24, 25] },
+            { tag: "wrap=true, mode=Center", wrap: true, mode: Tumbler.Center, expectedVisibleIndices: [18, 19, 20, 21, 22] },
+            { tag: "wrap=true, mode=End", wrap: true, mode: Tumbler.End, expectedVisibleIndices: [16, 17, 18, 19, 20] },
+            // Same as Beginning; should start at 20.
+            { tag: "wrap=true, mode=Contain", wrap: true, mode: Tumbler.Contain, expectedVisibleIndices: [21, 22, 23, 24, 25] },
+            { tag: "wrap=true, mode=SnapPosition", wrap: true, mode: Tumbler.SnapPosition, expectedVisibleIndices: [18, 19, 20, 21, 22] },
+            { tag: "wrap=false, mode=Beginning", wrap: false, mode: Tumbler.Beginning, expectedVisibleIndices: [20, 21, 22, 23, 24] },
+            { tag: "wrap=false, mode=Center", wrap: false, mode: Tumbler.Center, expectedVisibleIndices: [18, 19, 20, 21, 22] },
+            { tag: "wrap=false, mode=End", wrap: false, mode: Tumbler.End, expectedVisibleIndices: [16, 17, 18, 19, 20] },
+            { tag: "wrap=false, mode=Visible", wrap: false, mode: Tumbler.Visible, expectedVisibleIndices: [16, 17, 18, 19, 20] },
+            { tag: "wrap=false, mode=Contain", wrap: false, mode: Tumbler.Contain, expectedVisibleIndices: [16, 17, 18, 19, 20] },
+            { tag: "wrap=false, mode=SnapPosition", wrap: false, mode: Tumbler.SnapPosition, expectedVisibleIndices: [18, 19, 20, 21, 22] }
+        ]
+    }
+
+    function test_positionViewAtIndex(data) {
+        createTumbler({ wrap: data.wrap, model: 40, visibleItemCount: 5 })
+        compare(tumbler.wrap, data.wrap)
+
+        waitForRendering(tumbler)
+
+        tumbler.positionViewAtIndex(20, data.mode)
+        tryCompare(tumbler, "moving", false)
+
+        compare(tumbler.visibleItemCount, 5)
+        for (var i = 0; i < 5; ++i) {
+            // Find the item through its text, as that's easier than child/itemAt().
+            var text = data.expectedVisibleIndices[i].toString()
+            var item = findDelegateWithText(tumblerView, text)
+            verify(item, "found no item with text \"" + text + "\"")
+            compare(item.text, data.expectedVisibleIndices[i].toString())
+
+            // Ensure that it's at the position we expect.
+            var expectedPos = itemTopLeftPos(i)
+            var actualPos = testCase.mapFromItem(item, 0, 0)
+            compare(actualPos.x, expectedPos.x, "expected delegate with text " + item.text
+                + " to have an x pos of " + expectedPos.x + " but it was " + actualPos.x)
+            compare(actualPos.y, expectedPos.y, "expected delegate with text " + item.text
+                + " to have an y pos of " + expectedPos.y + " but it was " + actualPos.y)
+        }
+    }
 }