Android Open Source - field-data-app Image Colour Picker Fragment

• Back to Development/data  ↑

From Project

Back to project page field-data-app.

License

The source code is released under:

MIT License

Java Source Code

package nz.cri.gns.springs.fragments;
//  w w  w . j  a v a 2s . c  om
import java.io.Serializable;

import nz.cri.gns.springs.R;
import nz.cri.gns.springs.util.DataStatistics;
import nz.cri.gns.springs.util.UiUtil;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;

/**
 * Dialog box which allows a user to select a colour from an image.
 * @author duncanw
 */
public class ImageColourPickerFragment extends SpringsDialogFragment implements OnTouchListener {
  
  /**
   * Width of the image display area, in pixels.
   */
  public static final int IMAGE_WIDTH = 700;
  
  /**
   * Width of the image display area, in pixels.
   */
  public static final int IMAGE_HEIGHT = 700;

  private Integer selectedColour;
  private String imageFile;
  
  private static final String IMAGE_FILE_KEY = "imageFile";
  
  /**
   * Key for the intent extra-data containing the RGB integer value of the selected colour.
   * (returned to the onActivityResult method of the activity that opened the dialog box).
   */
  public static final String COLOUR_KEY = "colourKey";
  
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
      
      View rootView = inflater.inflate(R.layout.dialog_colour_picker, container, false);
      getDialog().setTitle(R.string.image_colour_picker_dialog_title);
      
      displayImage(rootView);
      addOkButtonListener(rootView);
      addCancelButtonListener(rootView);
      
      setColour(rootView);
      
      return rootView;
    }
    
    private void setColour(View rootView) {
      if (selectedColour != null)  {
        View colour = rootView.findViewById(R.id.selected_image_colour);
        colour.setBackgroundColor(selectedColour);
      }
    }
    
    @Override
    public void onSaveInstanceState(Bundle instanceState) {
      super.onSaveInstanceState(instanceState);
      instanceState.putString(IMAGE_FILE_KEY, imageFile);
      if (selectedColour != null) {
        instanceState.putSerializable(COLOUR_KEY, selectedColour);
      }
    }
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      if (savedInstanceState != null) {
        imageFile = savedInstanceState.getString(IMAGE_FILE_KEY);
        Serializable colour = savedInstanceState.getSerializable(COLOUR_KEY);
        if (colour != null) {
          selectedColour = (Integer)colour;
        }
      }
    }      
    
    public void displayImage(View rootView) {
      
      ImageView imgView = (ImageView) rootView.findViewById(R.id.colour_picker_image);       
        Bitmap bitmap;
        if (imageFile == null) {
          bitmap = UiUtil.loadImage(this.getResources(), R.drawable.colour_picker, IMAGE_WIDTH, IMAGE_HEIGHT);
        } else {
          bitmap = UiUtil.loadImage(imageFile, IMAGE_WIDTH, IMAGE_HEIGHT);
        }
        
        imgView.setImageBitmap(bitmap);        
        imgView.setAdjustViewBounds(true);
        imgView.setMaxWidth(IMAGE_WIDTH);
        imgView.setMaxHeight(IMAGE_HEIGHT);
        imgView.setOnTouchListener(this);
    }
    
    
    public void addOkButtonListener(final View rootView) {
      
      Button okButton = (Button) rootView.findViewById(R.id.ok_colour_select_button);
      okButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
              dismiss();
              if (selectedColour != null) {
                  getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_OK, new Intent().putExtra(COLOUR_KEY, selectedColour));
              }
            }
        });
    } 
    
    public void addCancelButtonListener(final View rootView) {
      
      Button cancelButton = (Button) rootView.findViewById(R.id.cancel_colour_select_button);
      cancelButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
              dismiss();
            }
        });
    }    
    
    
  @Override
  public boolean onTouch(View view, MotionEvent event) {
    
    if (event.getAction() == MotionEvent.ACTION_DOWN) {
      ImageView imageView = (ImageView)view;
      BitmapDrawable image = (BitmapDrawable)imageView.getDrawable();
      selectedColour = getColour(imageView, image.getBitmap(), (int)event.getX(), (int)event.getY());
      setColour(this.getView());
    }
    
    return true;
  }
  
  
  private int getColour(ImageView imageView, Bitmap image, int x, int y) {
    
    // The selected colour is determined by averaging the RGB values
    // of the pixels in a square around the point where the touch
    // was detected. This is to allow for images where an area's visible colour
    // is made up of pixels of varying colours, so individual pixels
    // may not be represent the expected colour selection.
    int gridRadius = 5;
    int minX = Math.max(0, x - gridRadius);
    int minY = Math.max(0, y - gridRadius);
    int maxX = Math.min(image.getWidth(), x + gridRadius);
    int maxY = Math.min(image.getHeight(), y + gridRadius);
    
    int pixelCount = (1 + maxX - minX) * (1 + maxY - minY);
    int[] redValues = new int[pixelCount];
    int[] greenValues = new int[pixelCount];
    int[] blueValues = new int[pixelCount];
    int i = 0;
    for (x = minX; x <= maxX; x++) {
      int transformedX = transformX(imageView, image, (double)x);
      for (y = minY; y <= maxY; y++) {
        int transformedY = transformY(imageView, image, (double)y);
        int pixel = image.getPixel(transformedX, transformedY);
        redValues[i] = Color.red(pixel);
        greenValues[i] = Color.green(pixel);
        blueValues[i] = Color.blue(pixel);
        i++;
      }
    }
    
    int red = new DataStatistics(redValues).calculate().getWeightedAverage();
    int green = new DataStatistics(greenValues).calculate().getWeightedAverage();
    int blue = new DataStatistics(blueValues).calculate().getWeightedAverage();
    
    return Color.rgb(red, green, blue);
  }
  

  private int transformX(ImageView imageView, Bitmap image, double x) {
    double displayWidth = imageView.getWidth();
    int transformedX = (int)(((double)image.getWidth() / displayWidth) * x);
    return Math.min(image.getWidth() - 1, transformedX);
  }
  
  private int transformY(ImageView imageView, Bitmap image, double y) {
    double displayHeight = imageView.getHeight();
    int transformedY = (int)(((double)image.getHeight() / displayHeight) * y);
    return Math.min(image.getHeight() - 1, transformedY);
  }
  
  public void setImageFile(String file) {
    this.imageFile = file;
  }
  
  public void setInitialColour(Integer colour) {
    this.selectedColour = colour;
  }

}

Java Source Code List

• Back to Development/data  ↑