Class: ImageViewer

Inherits:
Qt::MainWindow
  • Object
show all
Defined in:
ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb

Instance Method Summary collapse

Constructor Details

#initialize(parent = nil) ⇒ ImageViewer

Returns a new instance of ImageViewer.



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 37

def initialize(parent = nil)
	super(parent)
	@imageLabel = Qt::Label.new
	@imageLabel.backgroundRole = Qt::Palette::Base
	@imageLabel.setSizePolicy(Qt::SizePolicy::Ignored, Qt::SizePolicy::Ignored)
	@imageLabel.scaledContents = true

	@scrollArea = Qt::ScrollArea.new
	@scrollArea.backgroundRole = Qt::Palette::Dark
	@scrollArea.widget = @imageLabel
	setCentralWidget(@scrollArea)

	createActions()
	createMenus()

	setWindowTitle(tr("Image Viewer"))
	resize(500, 400)
	@printer = Qt::Printer.new
end

Instance Method Details

#about ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 117

def about()
	Qt::MessageBox::about(self, tr("About Image Viewer"),
			tr("<p>The <b>Image Viewer</b> example shows how to combine Qt::Label " +
			"and Qt::ScrollArea to display an image. Qt::Label is typically used " +
			"for displaying a text, but it can also display an image. " +
			"Qt::ScrollArea provides a scrolling view around another widget. " +
			"If the child widget exceeds the size of the frame, Qt::ScrollArea " +
			"automatically provides scroll bars. </p><p>The example " +
			"demonstrates how Qt::Label's ability to scale its contents " +
			"(Qt::Label::scaledContents), and Qt::ScrollArea's ability to " +
			"automatically resize its contents " +
			"(Qt::ScrollArea.widgetResizable), can be used to implement " +
			"zooming and scaling features. </p><p>In addition the example " +
			"shows how to use Qt::Painter to print an image.</p>"))
end

#adjustScrollBar(scrollBar, factor) ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 215

def adjustScrollBar(scrollBar, factor)
	scrollBar.value = factor * scrollBar.value
							+ ((factor - 1) * scrollBar.pageStep/2)
end

#createActions ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 133

def createActions()
	@openAct = Qt::Action.new(tr("&Open..."), self)
	@openAct.shortcut = Qt::KeySequence.new(tr("Ctrl+O"))
	connect(@openAct, SIGNAL('triggered()'), self, SLOT('open()'))

	@printAct = Qt::Action.new(tr("&Print..."), self)
	@printAct.shortcut = Qt::KeySequence.new(tr("Ctrl+P"))
	@printAct.enabled = false
	connect(@printAct, SIGNAL('triggered()'), self, SLOT('print()'))

	@exitAct = Qt::Action.new(tr("E&xit"), self)
	@exitAct.shortcut = Qt::KeySequence.new(tr("Ctrl+Q"))
	connect(@exitAct, SIGNAL('triggered()'), self, SLOT('close()'))

	@zoomInAct = Qt::Action.new(tr("Zoom &In (25%)"), self)
	@zoomInAct.shortcut = Qt::KeySequence.new(tr("Ctrl++"))
	@zoomInAct.enabled = false
	connect(@zoomInAct, SIGNAL('triggered()'), self, SLOT('zoomIn()'))

	@zoomOutAct = Qt::Action.new(tr("Zoom &Out (25%)"), self)
	@zoomOutAct.shortcut = Qt::KeySequence.new(tr("Ctrl+-"))
	@zoomOutAct.enabled = false
	connect(@zoomOutAct, SIGNAL('triggered()'), self, SLOT('zoomOut()'))

	@normalSizeAct = Qt::Action.new(tr("&Normal Size"), self)
	@normalSizeAct.shortcut = Qt::KeySequence.new(tr("Ctrl+S"))
	@normalSizeAct.enabled = false
	connect(@normalSizeAct, SIGNAL('triggered()'), self, SLOT('normalSize()'))

	@fitToWindowAct = Qt::Action.new(tr("&Fit to Window"), self)
	@fitToWindowAct.enabled = false
	@fitToWindowAct.checkable = true
	@fitToWindowAct.shortcut = Qt::KeySequence.new(tr("Ctrl+F"))
	connect(@fitToWindowAct, SIGNAL('triggered()'), self, SLOT('fitToWindow()'))

	@aboutAct = Qt::Action.new(tr("&About"), self)
	connect(@aboutAct, SIGNAL('triggered()'), self, SLOT('about()'))

	@aboutQtAct = Qt::Action.new(tr("About &Qt"), self)
	connect(@aboutQtAct, SIGNAL('triggered()'), $qApp, SLOT('aboutQt()'))
end

#createMenus ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 175

def createMenus()
	@fileMenu = Qt::Menu.new(tr("&File"), self)
	@fileMenu.addAction(@openAct)
	@fileMenu.addAction(@printAct)
	@fileMenu.addSeparator()
	@fileMenu.addAction(@exitAct)

	@viewMenu = Qt::Menu.new(tr("&View"), self)
	@viewMenu.addAction(@zoomInAct)
	@viewMenu.addAction(@zoomOutAct)
	@viewMenu.addAction(@normalSizeAct)
	@viewMenu.addSeparator()
	@viewMenu.addAction(@fitToWindowAct)

	@helpMenu = Qt::Menu.new(tr("&Help"), self)
	@helpMenu.addAction(@aboutAct)
	@helpMenu.addAction(@aboutQtAct)

	menuBar().addMenu(@fileMenu)
	menuBar().addMenu(@viewMenu)
	menuBar().addMenu(@helpMenu)
end

#fitToWindow ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 106

def fitToWindow()
	fitToWindow = @fitToWindowAct.checked?
	@scrollArea.widgetResizable = fitToWindow
	if !fitToWindow
		@imageLabel.adjustSize()
	end

	updateActions()
end

#normalSize ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 101

def normalSize()
	@imageLabel.adjustSize()
	@scaleFactor = 1.0
end

#open ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 57

def open()
	fileName = Qt::FileDialog::getOpenFileName(self,
									tr("Open File"), Qt::Dir.currentPath())
	if !fileName.nil?
		image = Qt::Image.new(fileName)
		if image.nil?
			Qt::MessageBox.information(self, tr("Image Viewer"),
									tr("Cannot load %s." % fileName))
			return
		end
		@imageLabel.pixmap = Qt::Pixmap.fromImage(image)
		@scaleFactor = 1.0

		@printAct.enabled = true
		@fitToWindowAct.enabled = true
		updateActions()

		if !@fitToWindowAct.checked?
			@imageLabel.adjustSize
		end
	end
end

#print ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 80

def print()
	dialog = Qt::PrintDialog.new(@printer, self)
	if dialog.exec
		painter = Qt::Painter.new(@printer)
		rect = painter.viewport
		size = @imageLabel.pixmap.size
		size.scale(rect.size(), Qt::KeepAspectRatio)
		painter.viewport = Qt::Rect.new(rect.x, rect.y, size.width, size.height)
		painter.window = @imageLabel.pixmap.rect
		painter.drawPixmap(0, 0, @imageLabel.pixmap)
	end
end

#scaleImage(factor) ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 204

def scaleImage(factor)
	@scaleFactor *= factor
	@imageLabel.resize(@imageLabel.pixmap().size() * @scaleFactor)

	adjustScrollBar(@scrollArea.horizontalScrollBar(), factor)
	adjustScrollBar(@scrollArea.verticalScrollBar(), factor)

	@zoomInAct.enabled = @scaleFactor < 3.0
	@zoomOutAct.enabled = @scaleFactor > 0.333
end

#updateActions ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 198

def updateActions()
	@zoomInAct.enabled = !@fitToWindowAct.checked?
	@zoomOutAct.enabled = !@fitToWindowAct.checked?
	@normalSizeAct.enabled = !@fitToWindowAct.checked?
end

#zoomIn ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 93

def zoomIn()
	scaleImage(1.25)
end

#zoomOut ⇒ Object 



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# File 'ext/ruby/qtruby/examples/widgets/imageviewer/imageviewer.rb', line 97

def zoomOut()
	scaleImage(0.8)
end