Move views up when SnackBar appears in Coordinator

问题:

I have a TextView at the bottom of the CoordinatorLayout.

But when I show a SnackBar , it will cover the TextView.

I know I have to customize a Behavior for the TextView and override layoutDependsOn and onDependentViewChanged,but it doesn't fix very well.

Could you give me some advice if you know? Thanks.

回答1:

You need to add a behavior to your LinearLayout and embed it in a CoordinatorLayout.

Here is how you do that.

MoveUpwardBehavior.class

import android.os.Build;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.Snackbar;
import android.view.View;


public class MoveUpwardBehavior extends CoordinatorLayout.Behavior<View> {
    private static final boolean SNACKBAR_BEHAVIOR_ENABLED;

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, View child, View dependency) {
        return SNACKBAR_BEHAVIOR_ENABLED && dependency instanceof Snackbar.SnackbarLayout;
    }

    @Override
    public boolean onDependentViewChanged(CoordinatorLayout parent, View child, View dependency) {
        float translationY = Math.min(0, dependency.getTranslationY() - dependency.getHeight());
        child.setTranslationY(translationY);
        return true;
    }

    static {
        SNACKBAR_BEHAVIOR_ENABLED = Build.VERSION.SDK_INT >= 11;
    }
}

CustomLinearLayout.class

import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.util.AttributeSet;
import android.widget.LinearLayout;

@CoordinatorLayout.DefaultBehavior(MoveUpwardBehavior.class)
public class CustomLinearLayout extends LinearLayout {
    public CustomLinearLayout(Context context) {
        super(context);
    }

    public CustomLinearLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomLinearLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }
}

Sample xml->activity_home

Here user.example.charu.its2017huree is my package name replace it with yours!

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:fitsSystemWindows="true"
        android:layout_height="match_parent">
        <user.example.charu.its2017huree.CustomLinearLayout
            android:background="#098"
            android:gravity="bottom"
            android:id="@+id/linearLayout"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">
            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Hello world" />
        </user.example.charu.its2017huree.CustomLinearLayout>

Finally in my Activity called HomeActivity

public class HomeActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        CustomLinearLayout customLinearLayout = (CustomLinearLayout) findViewById(R.id.linearLayout);
        Snackbar.make(customLinearLayout, "Text to display", Snackbar.LENGTH_LONG).show();

    }

}

Source is from this example.

回答2:

It the TextView is a direct child of a CoordinatorLayout, just add

app:layout_dodgeInsetEdges="bottom"

in the TextView attributes.

Magic!