require 'Qt'
require 'tempfile'

# This class implements a dialog with a screenshot display area and a
# screenshot button
class ScreenshotDialog < Qt::Dialog

  slots 'button_clicked()'

  def initialize(parent = nil, name = nil)

    super

    setWindowTitle("Screenshot Saver")

    resize(400, 120)

    layout = Qt::VBoxLayout.new
    setLayout(layout)

    @image = Qt::Label.new("Press the button to fetch a screenshot", self)
    layout.addWidget(@image)

    button = Qt::PushButton.new('Screenshot', self)
    button.setFont(Qt::Font.new('Times', 18, Qt::Font::Bold))
    layout.addWidget(button)

    connect(button, SIGNAL('clicked()'), SLOT('button_clicked()'))

  end

  def button_clicked
    view = RBA::Application.instance.main_window.current_view
    if view
      tmp = Tempfile.new("klayout-screenshot")
      view.save_image(tmp.path, 400, 400)
      @image.setPixmap(Qt::Pixmap.new(tmp.path))
    end
  end

end

# Locate the main window's qtruby object:
qt_main_window = Qt::Application.topLevelWidgets.select { |w| w.class.to_s == "lay::MainWindow" } [0]

# Instantiate the dialog and make it visible initially.
# Passing the $main_window will make it stay on top of the main window.
$dialog = ScreenshotDialog.new(qt_main_window)
$dialog.show

# It is important to run the application in the script so that exceptions are caught 
RBA::Application.instance.exec