//  GesturesDemoScalingActivity.java  Copyright (c) Kari Laitinen

//  http://www.naturalprogramming.com/

//  2019-09-14  File created based on GesturesDemoActivity.java.
//  2019-09-14  Last modification.

/*
    This is an improved version of the app GesturesDemo.
    
    This version can detect scaling gestures.


*/

package gestures.demo.scaling ;

import android.app.Activity ;
import android.os.Bundle ;
import android.graphics.* ;  // Classes Canvas, Color, Paint, RectF, etc.
import android.view.View ;
import android.view.MotionEvent ;
import android.view.GestureDetector ;
import android.view.ScaleGestureDetector ;
import android.content.Context ;
import java.util.ArrayList ;


final class GesturesDemoView extends View
                             implements GestureDetector.OnGestureListener,
                                        ScaleGestureDetector.OnScaleGestureListener
{
   GestureDetector gesture_detector ;
   ScaleGestureDetector scale_gesture_detector ;

   ArrayList<String> text_lines_to_screen = new ArrayList<String>() ;

   public GesturesDemoView( Context context ) 
   {
      super( context ) ;

      gesture_detector = new GestureDetector( context, this ) ;
      
      scale_gesture_detector = new ScaleGestureDetector( context, this ) ;

      text_lines_to_screen.add( "With this application, you can" ) ;
      text_lines_to_screen.add( "explore which gesture events" ) ;
      text_lines_to_screen.add( "take place when you play" ) ;
      text_lines_to_screen.add( "with the touch screen." ) ;
      text_lines_to_screen.add( "" ) ;

      setBackgroundColor( 0xFFFFFFE0 ) ; // Light Yellow
   }

   public boolean onDown( MotionEvent motion_event )
   {
      text_lines_to_screen.add( "onDown()" ) ;

      invalidate() ;

      return true ;
   }

   public boolean onFling( MotionEvent first_down_motion,
                           MotionEvent last_move_motion,
                           float velocity_x, float velocity_y )
   {
      text_lines_to_screen.add( "onFling()" ) ;

      invalidate() ;

      return true ;
   }

   public void onLongPress( MotionEvent first_down_motion )
   {
      text_lines_to_screen.add( "onLongPress()" ) ;

      invalidate() ;
   }

   public boolean onScroll( MotionEvent first_down_motion,
                            MotionEvent last_move_motion,
                            float distance_x, float distance_y )
   {
      text_lines_to_screen.add( "onScroll()" ) ;

      invalidate() ;

      return true ;
   }

   public void onShowPress( MotionEvent down_motion )
   {
      text_lines_to_screen.add( "onShowPress()" ) ;

      invalidate() ;
   }

   public boolean onSingleTapUp( MotionEvent up_motion )
   {
      text_lines_to_screen.add( "onSingleTapUp()" ) ;

      invalidate() ;

      return true ;
   }

   public boolean onScaleBegin( ScaleGestureDetector detector )
   {
      text_lines_to_screen.add( "onScaleBegin()" ) ;

      invalidate() ;

      return true ;
   }

   public boolean onScale( ScaleGestureDetector detector )
   {
      text_lines_to_screen.add( "onScale()" ) ;

      invalidate() ;

      return true ;
   }

   public void onScaleEnd( ScaleGestureDetector detector )
   {
      text_lines_to_screen.add( "onScaleEnd()" ) ;

      invalidate() ;
   }

   

   public boolean onTouchEvent ( MotionEvent motion_event )
   {
      gesture_detector.onTouchEvent( motion_event ) ;
      
      scale_gesture_detector.onTouchEvent( motion_event ) ;

      return true ;
   }

   protected void onDraw( Canvas canvas ) 
   {
      Paint text_paint = new Paint() ;
      text_paint.setStyle( Paint.Style.STROKE ) ;
      text_paint.setTextSize( 24 ) ;

      // We'll print only 10 lines to the screen.
      // The older lines from the beginning of the list will
      // be deleted.

      while ( text_lines_to_screen.size() > 10 )
      {
         text_lines_to_screen.remove( 0 ) ;
      }

      for ( int line_index  =  0 ;
                line_index  <  text_lines_to_screen.size() ;
                line_index  ++ )
      {
         String text_line_to_screen = text_lines_to_screen.get( line_index ) ;

         if ( text_line_to_screen.equals( "onDown()" ) )
         {
            text_paint.setColor( Color.BLACK ) ;
         }
         else if ( text_line_to_screen.equals( "onFling()" ) )
         {
            text_paint.setColor( Color.BLUE ) ;
         }
         else if ( text_line_to_screen.equals( "onLongPress()" ) )
         {
            text_paint.setColor( Color.RED ) ;
         }
         else if ( text_line_to_screen.equals( "onScroll()" ) )
         {
            text_paint.setColor( Color.GRAY ) ;
         }
         else if ( text_line_to_screen.equals( "onShowPress()" ) )
         {
            text_paint.setColor( Color.MAGENTA ) ;
         }
         else if ( text_line_to_screen.equals( "onSingleTapUp()" ) )
         {
            text_paint.setColor( Color.CYAN ) ;
         }
         else if ( text_line_to_screen.equals( "onScaleBegin()" ) )
         {
            text_paint.setColor( 0xFFDC143C ) ; // Crimson
         }
         else if ( text_line_to_screen.equals( "onScale()" ) )
         {
            text_paint.setColor( 0xFFB8860B ) ; // DarkGoldenRod
         }
         else if ( text_line_to_screen.equals( "onScaleEnd()" ) )
         {
            text_paint.setColor( 0xFF8B0000 ) ; // DarkRed
         }

         canvas.drawText( text_line_to_screen,
                          20,  48 + 32 * line_index, text_paint ) ;
      }
   }
}


public class GesturesDemoScalingActivity extends Activity
{
   // onCreate() will be called when the activity is first created.
   
   public void onCreate( Bundle savedInstanceState )
   {
      super.onCreate( savedInstanceState ) ;
        
      setContentView( new GesturesDemoView( this ) ) ;
   }
}