qt: handle high precision wheel events on playback speed widget

This handles high precision wheel events through WheelToVLCConverter, but it does not start supporting high precision adjustment (although the slider does that). I'm not sure if we want to have high precision adjustment on the button itself.

Request review @chub.

modules/gui/qt/player/qml/controlbarcontrols/PlaybackSpeedButton.qml

@@ -44,16 +44,32 @@ PopupIconToolButton {
         Navigation.rightItem: root
     }
 
-    contentItem: T.Label {
-        verticalAlignment: Text.AlignVCenter
-        horizontalAlignment: Text.AlignHCenter
+    contentItem: Item {
+        implicitHeight: label.implicitHeight
+        implicitWidth: textMetrics.width
+
+        TextMetrics {
+            id: textMetrics
+            font: label.font
+            // '-' is for additional space if certain digits have more width with certain fonts
+            text: "0.00x-"
+        }
+
+        Text {
+            id: label
+
+            anchors.fill: parent
+
+            verticalAlignment: Text.AlignVCenter
+            horizontalAlignment: Text.AlignHCenter
 
-        font.pixelSize: VLCStyle.fontSize_normal
+            font.pixelSize: VLCStyle.fontSize_normal
 
-        text: !root.paintOnly ? qsTr("%1x").arg(+Player.rate.toFixed(2))
-                              : qsTr("1x")
+            text: !root.paintOnly ? qsTr("%1x").arg(+Player.rate.toFixed(2))
+                                  : qsTr("1x")
 
-        color: root.color
+            color: root.color
+        }
     }
 
     // TODO: Qt bug 6.2: QTBUG-103604
@@ -62,39 +78,53 @@ PopupIconToolButton {
 
         z: -1
 
+        WheelToVLCConverter {
+            id: wheelToVLC
+
+            function handle(steps: int) {
+                let func
+                if (steps > 0)
+                    func = root.popup.contentItem.slider.increase
+                else
+                    func = root.popup.contentItem.slider.decrease
+
+                for (let i = 0; i < Math.abs(steps); ++i)
+                    func()
+            }
+
+            Component.onCompleted: {
+                wheelUpDown.connect(wheelToVLC.handle)
+                wheelLeftRight.connect(wheelToVLC.handle)
+            }
+        }
+
         WheelHandler {
-            onWheel: (event) => {
+            orientation: Qt.Vertical | Qt.Horizontal
+
+            onWheel: (wheel) => {
                 if (!root.popup.contentItem || !root.popup.contentItem.slider) {
                     event.accepted = false
                     return
                 }
 
-                let delta = 0
-
-                if (event.angleDelta.x)
-                    delta = event.angleDelta.x
-                else if (event.angleDelta.y)
-                    delta = event.angleDelta.y
-                else {
-                    event.accepted = false
-                    return
+                // NOTE: Uncomment below to support (not only handle) high precision adjustment:
+                // if ((Math.abs(wheel.pixelDelta.x) % 120 > 0) || (Math.abs(wheel.pixelDelta.y) % 120 > 0)) {
+                //     let delta = 0
+                //     if (Math.abs(wheel.pixelDelta.x) > Math.abs(wheel.pixelDelta.y))
+                //         delta = wheel.pixelDelta.x
+                //     else
+                //         delta = wheel.pixelDelta.y
+
+                //     if (wheel.inverted)
+                //         delta = -delta
+
+                //     root.popup.contentItem.slider.value += 0.01 * delta
+                // } else
+                {
+                    wheelToVLC.qmlWheelEvent(wheel)
                 }
 
-                if (event.inverted)
-                    delta = -delta
-
-                event.accepted = true
-
-                delta = delta / 8 / 15
-
-                let func
-                if (delta > 0)
-                    func = root.popup.contentItem.slider.increase
-                else
-                    func = root.popup.contentItem.slider.decrease
-
-                for (let i = 0; i < Math.ceil(Math.abs(delta)); ++i)
-                    func()
+                wheel.accepted = true
             }
         }