CopyWebView.java

package com.alorma.github.ui.view;

import android.content.Context;
import android.graphics.Color;
import android.os.Build;
import android.util.AttributeSet;
import android.view.ActionMode;
import android.view.GestureDetector;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.ViewParent;
import android.webkit.JavascriptInterface;
import android.webkit.WebSettings;
import android.webkit.WebView;
import com.alorma.github.R;
import com.mikepenz.google_material_typeface_library.GoogleMaterial;
import com.mikepenz.iconics.IconicsDrawable;

/**
 * http://stackoverflow.com/a/29353049/325479
 * Created by mikepenz on 20.06.15.
 */
public class CopyWebView extends WebView {

  // setting custom action bar
  private ActionMode mActionMode;
  private ActionMode.Callback mSelectActionModeCallback;
  private GestureDetector mDetector;
  private WebViewListener mWebViewListener;

  // override all other constructor to avoid crash
  public CopyWebView(Context context) {
    this(context, null);
  }

  public CopyWebView(Context context, AttributeSet attrs) {
    this(context, attrs, -1);
  }

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

    WebSettings webviewSettings = getSettings();
    webviewSettings.setJavaScriptEnabled(true);
    addJavascriptInterface(new WebAppInterface(), "JSInterface");

    mDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
      @Override
      public void onLongPress(MotionEvent e) {
        startActionMode(mSelectActionModeCallback);
      }

            /*
            @Override
            public boolean onSingleTapUp(MotionEvent e) {
                if (mActionMode != null) {
                    mActionMode.finish();
                    return true;
                }
                return false;
            }
            */
    });
  }

  // this will over ride the default action bar on long press
  @Override
  public ActionMode startActionMode(android.view.ActionMode.Callback callback) {
    ViewParent parent = getParent();
    if (parent == null) {
      return null;
    }
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
      String name = callback.getClass().toString();
      if (name.contains("SelectActionModeCallback")) {
        mSelectActionModeCallback = callback;
      }
    }
    CustomActionModeCallback mActionModeCallback = new CustomActionModeCallback();
    return parent.startActionModeForChild(this, mActionModeCallback);
  }

  /**
   * a small helper javascrip function to copy the selected text
   */
  private void getSelectedData() {

    String js = "(function getSelectedText() {" +
        "var txt;" +
        "if (window.getSelection) {" +
        "txt = window.getSelection().toString();" +
        "} else if (window.document.getSelection) {" +
        "txt = window.document.getSelection().toString();" +
        "} else if (window.document.selection) {" +
        "txt = window.document.selection.createRange().text;" +
        "}" +
        "JSInterface.getText(txt);" +
        "})()";
    // calling the js function
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
      evaluateJavascript("javascript:" + js, null);
    } else {
      loadUrl("javascript:" + js);
    }
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    // Send the event to our gesture detector
    // If it is implemented, there will be a return value
    if (mDetector != null) {
      mDetector.onTouchEvent(event);
    }
    // If the detected gesture is unimplemented, send it to the superclass
    return super.onTouchEvent(event);
  }

  public void setWebViewListener(WebViewListener webViewListener) {
    mWebViewListener = webViewListener;
  }

  /**
   * listener interface
   */
  public interface WebViewListener {
    void onTextCopy(String text);
  }

  /**
   * A ActionModeCallback
   */
  private class CustomActionModeCallback implements ActionMode.Callback {

    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
      mActionMode = mode;
      MenuInflater inflater = mode.getMenuInflater();
      inflater.inflate(R.menu.menu_web_view_copy, menu);

      menu.findItem(R.id.copy)
          .setIcon(new IconicsDrawable(CopyWebView.this.getContext(), GoogleMaterial.Icon.gmd_content_copy).color(Color.WHITE).actionBar());
      menu.findItem(R.id.share)
          .setIcon(new IconicsDrawable(CopyWebView.this.getContext(), GoogleMaterial.Icon.gmd_share).color(Color.WHITE).actionBar());

      return true;
    }

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
      return false;
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {

      switch (item.getItemId()) {
        case R.id.copy:
          getSelectedData();
          mode.finish();
          return true;
        case R.id.share:
          mode.finish();
          return true;
        default:
          mode.finish();
          return false;
      }
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        clearFocus();
      } else {
        if (mSelectActionModeCallback != null) {
          mSelectActionModeCallback.onDestroyActionMode(mode);
        }
        mActionMode = null;
      }
    }
  }

  /**
   * a helper interface class to call the WebViewListener.onTextCopy
   */
  public class WebAppInterface {
    @JavascriptInterface
    public void getText(String text) {
      if (mWebViewListener != null) {
        mWebViewListener.onTextCopy(text);
      }
    }
  }
}