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ViewsSet constraint height percent with databinding
I have a bar that should have a height according to the viewmodel.heartStrengthLiveData value (0..100). I want to set height with app:layout_constraintHeight_percent="..." with databinding.
How can i do this?
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/heart_strength_bgc"
android:layout_width="@dimen/cardiogram_status_bar_width"
android:layout_height="0dp"
android:layout_marginEnd="@dimen/default_screen_margin"
android:background="@drawable/chart_widget_background_dark_gray"
app:layout_constraintBottom_toBottomOf="@+id/cardiogram_background_light"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="@+id/cardiogram_background_light" >
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/heart_strength"
android:layout_width="0dp"
android:layout_height="0dp"
app:heartStrength="@{viewmodel.heartStrengthLiveData}"
android:background="@drawable/chart_widget_background_light_gray"
android:backgroundTint="@color/turquoise"
app:layout_constraintHeight_percent="0"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
·
Santiago Trujillo
1 answers
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Update: Corrected XML.
In your ViewModel, set up something like this which include the LiveData and the BindingAdapter for the layout percent height attribute:
public MutableLiveData heartStrengthLiveData = new MutableLiveData<>(100f);
public float getHeartStrength() {
return (float) heartStrengthLiveData.getValue() / 100f;
}
@BindingAdapter("layout_constraintHeight_percent")
public static void setLayoutConstraintHeightPercent(View view, float percentHeight) {
ConstraintLayout layout = (ConstraintLayout) view.getParent();
ConstraintSet cs = new ConstraintSet();
cs.clone(layout);
cs.constrainPercentHeight(view.getId(), percentHeight);
cs.applyTo(layout);
}
In the layout, specify:
app:layout_constraintHeight_percent='@{viewmodel.heartStrength}'
app:layout_constraintHeight_default="percent"
A height percentage of 1.0 will not work if the default height is not set to "percent" which addresses the issue in your (now deleted) comment.
·
Santiago Trujillo
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