ZoomControl.qml Example File
declarative-camera/ZoomControl.qml
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import Qt 4.7
import QtMultimediaKit 1.1
Item {
id : zoomControl
property real currentZoom : 1
property real maximumZoom : 1
signal zoomTo(real value)
MouseArea {
id : mouseArea
anchors.fill: parent
property real initialZoom : 0
property real initialPos : 0
onPressed: {
initialPos = mouseY
initialZoom = zoomControl.currentZoom
}
onMousePositionChanged: {
if (pressed) {
var target = initialZoom * Math.pow(2, (initialPos-mouseY)/zoomControl.height);
target = Math.max(1, Math.min(target, zoomControl.maximumZoom))
zoomControl.zoomTo(target)
}
}
}
Item {
id : bar
x : 16
y : parent.height/4
width : 24
height : parent.height/2
opacity : 0
Rectangle {
anchors.fill: parent
smooth: true
radius: 8
border.color: "black"
border.width: 2
color: "white"
opacity: 0.3
}
Rectangle {
x : 0
y : parent.height * (1.0 - (zoomControl.currentZoom-1.0) / (zoomControl.maximumZoom-1.0))
width: parent.width
height: parent.height - y
smooth: true
radius: 8
color: "black"
opacity: 0.5
}
states: State {
name: "ShowBar"
when: mouseArea.pressed || zoomControl.currentZoom > 1.0
PropertyChanges { target: bar; opacity: 1 }
}
transitions: [
Transition {
to : "ShowBar"
NumberAnimation { properties: "opacity"; duration: 100 }
},
Transition {
from : "ShowBar"
NumberAnimation { properties: "opacity"; duration: 500 }
}
]
}
}