Display PopupWindow upon clicking a button?

Question

Currently, I have a button, within a Linear Layout, like so:

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="@string/open_popup"
        android:onClick="createPopup"/>
</LinearLayout>

I also have a createPopup extension (which does indeed execute when the button is clicked).

public void createPopup(View view) {

}

I have tried to create a PopupWindow with a TextView within it. I then called showAtLocation(parent, gravity, x, y) where parent is the root LinearLayout. gravity was Gravity.BOTTOM, x and y were both set to 10.

When I clicked the button, I received an IllegalStateException error where I called showAtLocation(). Here is the createPopup() function:

PopupWindow popUp;
LinearLayout layout;
LinearLayout main;
TextView value;
LayoutParams params;
boolean click = true;
public void createPopup(View view) {
    popUp = new PopupWindow(this);
    layout = new LinearLayout(this);
    main = (LinearLayout) findViewById(R.id.parent);
    value = new TextView(this);
    if(click) {
        popUp.showAtLocation(main, Gravity.BOTTOM, 10, 10);
        popUp.update(50, 50, 300, 80);
        click = false;
    } else {
        popUp.dismiss();
        click = true;
    }
    params = new LayoutParams(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT);
    layout.setOrientation(LinearLayout.VERTICAL);
    value.setText(R.string.message);
    layout.addView(value, params);
    popUp.setContentView(layout);
    setContentView(main);
    TextView status = (TextView) findViewById(R.id.status);
    status.setTextSize(28);
    status.setText("Status of Popup: Don't worry, you're never going to get this.");
}

What I would like to know is:

• What does that error mean?
• Why does it appear?
• How can I fix it?
• How do I create a simple popup window that appears at the click of a button?*

*I'd like to be able to create a function where it takes at least one parameter (which would be a String), and then create's a popup window that contains that String, as well as a button to close the popup window.

EDIT: Not sure if this is connected to the popup issue, but when I run the app, I get this error:

07-13 19:51:48.448 133-133/? E/[EGL-ERROR]: egl_image* _egl_create_image_ANDROID_native_buffer(egl_display*, egl_context*, EGLClientBuffer, EGLint*, void*):593: CHUN try create image with crop 0,0,0,0


                                            [ 07-13 19:51:48.448   133:  133 E/         ]
                                            CHUN map external image rgb 1024 x 600

SECOND EDIT: I've added relevant code above.

Answer 1

If you are looking at how to implement a Dialog, what I normally do is create a separate layout file, class file, and call it from where it needs to be shown. Dialogs show over the other activity in the center, and as far as I know, they cannot be moved.

When you want to show the dialog, you can call:

private void openMyDialog() {
    MyDialog dialog = new MyDialog(this);
    dialog.show();
}

MyDialog.java needs to extend Dialog and implement android.view.View.OnClickListener. It will contain any code necessary to save or control the elements on your layout. MyDialog.java:

import android.app.Activity;
import android.app.Dialog;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;

public class MyDialog extends Dialog implements android.view.View.OnClickListener {

    public Activity activity;

    public MyDialog() {
        super(null);
    }
    public MyDialog(Activity activity) {
        super(activity);
        this.activity = activity;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.my_dialog);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            default:
                break;
        }
        dismiss();
    }

}

my_dialog.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#1C1C1C">
<!-- Whatever your layout will consist of can go here -->

</RelativeLayout>

I hope this answers your question. If it does not, feel free to comment on this post. I do not know how to fix your error (as it is not the full error) but I do know how to implement custom Dialogs (or Popups) to go over your other activity.