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  1. Qt
  2. QTBUG-42194

Provide a way to force re-evaluation of MouseArea's containsMouse property

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    • 6f84a09dfbd15aac023580cf06e7b8c24f3b524c

      It is documented that a MouseArea's containsMouse property is only updated when the mouse actually moves:

      Warning: This property is not updated if the area moves under the mouse: containsMouse will not change. In addition, if hoverEnabled is false, containsMouse will only be valid when the mouse is pressed while the mouse cursor is inside the MouseArea.

      This presents problems for scenarios like the one below:

      import QtQuick 2.4
import QtQuick.Controls 1.3

Rectangle {
    id: mainMenu
    activeFocusOnTab: false
    width: 650
    height: 600

    ListView {
        id: listView
        anchors.centerIn: parent
        width: 200
        height: 300
        model: ListModel {
            Component.onCompleted: {
                for (var i = 0; i < 10; ++i) {
                    append({name: i + 1});
                }
            }
        }

        delegate: Rectangle {
            width: listView.width
            height: 30
            color: "black"

            Text {
                text: modelData
                color: mouseArea.containsMouse ? "white" : "grey"
                anchors.centerIn: parent
            }

            MouseArea {
                id: mouseArea
                anchors.fill: parent
                hoverEnabled: true
                onClicked: listView.model.remove(index)
            }
        }
    }
}

      The user would expect that by removing an item from the list, the item that takes the removed item's place (if any) would be highlighted, but it's not.

      There might not be a declarative way to solve this problem, but we could provide a function that simply checks the last mouse position and updates containsMouse on demand:

          // ...

    ListView {
        // ...

        delegate: Rectangle {
            // ...

            MouseArea {
                id: mouseArea
                anchors.fill: parent
                hoverEnabled: true
                onClicked: listView.model.remove(index)

                Connections {
                    target: listView
                    onCountChanged: mouseArea.refresh()
                    // or: onCountChanged: mouseArea.refreshContainsMouse()
                    // or: onCountChanged: mouseArea.checkIfContainsMouse()
                }
            }
        }
    }
}

        For Gerrit Dashboard: QTBUG-42194
        # Subject Branch Project Status CR V
        127724,5 QQuickWindow: Process a synthetic hover once per frame dev qt/qtdeclarative Status: MERGED +2 0

            srutledg Shawn Rutledge
            mitch_curtis Mitch Curtis
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            3 Vote for this issue
            Watchers:
            7 Start watching this issue

              Created:
              Updated:
              Resolved:

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