Processing - Zoom on clicked area then click again to zoom back out

I have a picture then used a flashlight type of light to only show where the mouse is hov over. That part of the code worked but now I want to use if/else statements to zoom in on the selected area then click again to zoom back out. Any way to zoom on specific area then back out of that area also helps. Really any help will be appreciated!

PImage ispy;

void setup () {
  size(1024,768); 
  ispy = loadImage("ispy2.jpeg");
}

void draw () { 
  loadPixels(); 
  ispy.loadPixels(); 
  for (int x = 0; x < width; x++) { 
    for (int y = 0; y < height; y++) {
      int loc = x+y*width;
      float r = red(ispy.pixels[loc]); 
      float g = green(ispy.pixels[loc]);
      float b = blue(ispy.pixels[loc]);
      float d = dist(mouseX, mouseY, x, y); //

      float factor = map(d, 0, 200, 2, 0); 
      pixels[loc] = color(r*factor, g*factor, b*factor); 
    }
  }
  updatePixels();
}