using System;
using System.ComponentModel;
using System.Windows.Forms;
using System.Drawing;
using System.IO;
using System.Resources;

/* ImageZoom accepts an image dragged onto ImageZoom.exe icon.
   Window resizing causes image to fill entire Form panel.
   Accepts remote file Drag/Drop into Form control.
   Clicking image causes image to toggle between original size and full Form size.
                                                 M. Gallant   03/14/2002  */

public class ImageZoom : Form 
{  
   private PictureBox pictureBox1;
   private string filepath = @".\\zoomimage.gif";  //default file
   private string caption =  "ImageZoom     M. Gallant  03/14/2002" ; 
   private string [] cmdargs;
   private Image image1;
   private bool originalSize = true ;
   private bool validimage = false;
   private string [] fdata  ;
   private ResourceManager rm;

   public ImageZoom() : base() 
   { 
      this.ClientSize = new Size(200,200) ;
      this.Text = this.caption ;
      this.AllowDrop = true;  // enable Drag/Drop for this form.

      pictureBox1 = new PictureBox() ;
      pictureBox1.Location = new Point(0,0) ;
      pictureBox1.ClientSize = this.ClientSize;     //set PictureBox size to starter size of Form
      Controls.Add(pictureBox1); 

      // To wire the event, create
      // a delegate instance and add it to the Click event.
      this.Click += new EventHandler(this.Form_Clicked);          // form-clicked 
      this.Resize += new EventHandler(this.Winresized);           // for form itself
      pictureBox1.Click += new EventHandler(this.Form_Clicked) ;

     // --------- Define Drag/Drop event handlers for this form control ---------------
      this.DragEnter += new DragEventHandler(this.form_DragEnter) ;
      this.DragDrop += new DragEventHandler(this.form_DragHandle) ;


    cmdargs = Environment.GetCommandLineArgs();
   if (cmdargs.Length >1) {
	// Console.WriteLine("CommandLine[1]: " + cmdargs[1]) ;
	filepath = cmdargs[1] ;
     if(File.Exists(filepath)) {
         try {
	image1 = Image.FromFile(filepath) ;
	validimage = true;
	pictureBox1.Image = image1 ;   // display the image
           }
        catch(OutOfMemoryException ome) {
	validimage = false ;   // invalid image file
	MessageBox.Show("ImageZoom:   filepath: " + filepath  + " is not a valid image file.", caption, 
	MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
          }
       }   // end if ...
     else {
	validimage=false;
	//MessageBox.Show("ImageZoom:   filepath: " + filepath  + " not found.", caption, 
	//MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }
    }  // end if(cmdargs..

  else  {     // if no image passed as argument, or dragged, use built-in default image resource
    rm = new ResourceManager("MigImages", this.GetType().Assembly);
    image1 = (Image) rm.GetObject("guitar"); 
    pictureBox1.Image = image1 ;   // display the image
    validimage=true;
  }

 } //end constructor


public bool validImage() {
  return validimage ;
 }

 
  // Event Handler for window resizing
 private void Winresized(object sender, EventArgs e)
  {
   // Stretches the image to fit the pictureBox after image is originally displayed actual size
    pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage ;
    // pictureBox1.ClientSize = new Size(this.ClientRectangle.Width, this.ClientRectangle.Height) ;
     pictureBox1.ClientSize = this.ClientSize;
    originalSize = false; 
  }


   // The event handler for Form click
   private void Form_Clicked(object sender, EventArgs e) 
   {
      if (originalSize) {
        pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage ;
   }
      else  {
        pictureBox1.SizeMode = PictureBoxSizeMode.Normal ;
      }
    originalSize = !originalSize ;   //toggle
   }


private void form_DragEnter(object sender, DragEventArgs e)
{
   if (e.Data.GetDataPresent(DataFormats.FileDrop))   // only accept external file drag/drops
      e.Effect = DragDropEffects.Copy;
   else
      e.Effect = DragDropEffects.None;
}


 private void form_DragHandle(object sender, DragEventArgs e) {
   fdata =  (string []) e.Data.GetData(DataFormats.FileDrop) ;  // cast to string array
   if ( verifyImage(fdata[0]))    // only update if a valid image file
	   pictureBox1.Image = Image.FromFile (fdata[0]);
  }


private bool verifyImage(String filepath) {    //don't handle dragged directories or non-image files.
 if(Directory.Exists(filepath)) {
	MessageBox.Show("ImageZoom:   filepath: " + filepath  + " is a directory.", caption,
	MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
	return false;
       }

 if(!File.Exists(filepath)) {
	MessageBox.Show("ImageZoom:   filepath: " + filepath  + " not found.", caption,
	MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
	return false;
       }

      try {
	Image image1 = Image.FromFile(filepath) ;
	return true;
        }
      catch(OutOfMemoryException ome) {
	MessageBox.Show("ImageZoom:   filepath: " + filepath  + " is not a valid image file.", caption,
	MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
	return false;
       }
 }



   // STAThreadAttribute indicates that Windows Forms uses the
   // single-threaded apartment model.
     [STAThreadAttribute]
   public static void Main(String[] args) 
   {
      ImageZoom zim = new ImageZoom() ;
      if (!zim.validImage())
	MessageBox.Show("ImageZoom:   Drag & Drop any image file into the \"ImageZoom\" Form", zim.caption,
	MessageBoxButtons.OK, MessageBoxIcon.Information);
          // zim.ShowDialog() ;   //modal dialog to show Form
         Application.Run(zim);
   }  
}