#region Using directives

using System;
using System.Collections.ObjectModel;
using System.Windows.Forms;

using Microsoft.VisualBasic.ApplicationServices;

#endregion

namespace MultiSDISample {
  public class MultiSDIApplication : WindowsFormsApplicationBase {

    private static MultiSDIApplication application;
    internal static MultiSDIApplication Application {
      get {
        if( application == null ) {
          application = new MultiSDIApplication();
        }
        return application;
      }
    }
    
    public MultiSDIApplication() {

      // This ensures the underlying single-SDI framework is employed, 
      // and OnStartupNextInstance is fired
      this.IsSingleInstance = true;

      // Needed for multi-SDI since no form is the main form
      this.ShutdownStyle = ShutdownMode.AfterAllFormsClose;
    }

    // Create first top-level form
    protected override void OnCreateMainForm() {
      this.MainForm = this.CreateTopLevelWindow(this.CommandLineArgs);
    }

    // Create subsequent top-level form
    protected override void OnStartupNextInstance(StartupNextInstanceEventArgs e) {
      this.CreateTopLevelWindow(e.CommandLine);
    }

    private TopLevelForm CreateTopLevelWindow(ReadOnlyCollection<string> args) {
      // Get file name, if provided
      string fileName = (args.Count > 0 ? args[0] : null);

      // Create a new top-level form
      return TopLevelForm.CreateTopLevelWindow(fileName);
    }
    
    #region Menu management - was in MultiSDIApplicationContext file

    public void AddTopLevelForm(Form form) {

      // Add form to collection of forms and
      // watch for it to activate and close
      form.Activated += Form_Activated;
      form.FormClosed += Form_FormClosed;

      // Set initial top level form to activate
      if( this.OpenForms.Count == 1 ) this.MainForm = form;
    }

    public void AddWindowMenu(ToolStripMenuItem windowMenu) {
      // Handle tool strip menu item's drop down opening event
      windowMenu.DropDownOpening += windowMenu_DropDownOpening;
    }

    void Form_Activated(object sender, EventArgs e) {
      // Whichever form activated last is the current top-level form
      this.MainForm = (Form)sender;
    }

    void Form_FormClosed(object sender, FormClosedEventArgs e) {
      // Set a new "main" if necessary
      Form form = (Form)sender;
      if( (form == this.MainForm) && (this.OpenForms.Count > 0) ) {
        this.MainForm = (Form)this.OpenForms[0];
      }
      form.Activated -= Form_Activated;
      form.FormClosed -= Form_FormClosed;
    }

    void windowMenu_DropDownOpening(object sender, EventArgs e) {
    
      ToolStripMenuItem menu = (ToolStripMenuItem)sender;

      // Clear current menu
      if( menu.DropDownItems.Count > 0 ) {
        menu.DropDown.Dispose();
      }
      menu.DropDown = new ToolStripDropDown();

      // Populate menu with one item for each open top-level form
      foreach( Form form in this.OpenForms ) {
        ToolStripMenuItem item = new ToolStripMenuItem();
        item.Text = form.Text;
        item.Tag = form;
        menu.DropDownItems.Add(item);

        item.Click += WindowMenuItem_Click;

        // Check currently active window
        if( form == this.MainForm )
          item.Checked = true;
      }
    }

    void WindowMenuItem_Click(object sender, EventArgs e) {
      // Activate top-level form based on selection
      ((Form)((ToolStripMenuItem)sender).Tag).Activate();
    }
    #endregion
  }
}