QML Binding only functions ones

jago

Hello!

I have two components: a Slider with property value and a Prompt with property promptValue. The Slider and the Prompt should both show the same value. With the buttons of the Prompt one can increment or decrement the value. In another Qml file I instantiate the slider and the prompt and use Bindings to make a bidirectional connection to the backend:

Slider Binding:

@MySlider {
id: slider
maximum: 450
minimum: 220
value: backendObject.backendVlaue

                                    Binding {
                                        target: backendObject
                                        property: "backendVlaue"
                                        value: slider.value

}@

Prompt Binding:

@Prompt {
id: prompt
max: 450
min: 220
promptValue: backendObject.backendValue

                                    Binding {
                                        target: backendObject
                                        property: "backendValue"
                                        value: prompt.promptValue
                                    }

}@

The thing is it only functions ones. Either i move the handle of the slider, then the value is updated and shown correctly both in slider and in the prompt. Or I push the buttons, then the handle and the prompt values are being updated and shown correctly. If I first move the slider, then push the buttons and then move the slider again, the values will not update. Or vice versa.
Can anyone comprehend the problem? As I understand the value should be updated automatically through Bindings and my two components use the same value, so why do they differ when I move the slider second time after pushing the buttons of the prompt?

thanx and best regards