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These are the tutorials written a while ago, plus one chapter called "Why QSkinny?". They will be part of the website once it is published.
63 lines
2.0 KiB
Plaintext
63 lines
2.0 KiB
Plaintext
---
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title: 6. (Scalable) graphics
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layout: docs
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---
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:doctitle: 6. (Scalable) graphics
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:notitle:
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== (Scalable) graphics
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QSkinny offers support for scalable graphics, i.e. rendering SVGs that
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adapt to a specific size. This means that when a graphic is embedded in
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a layout, it can change its size when the layout is growing or
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shrinking, while still maintaining a correct aspect ratio.
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Imagine the following code, which produces the image depicted below:
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[source]
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....
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auto horizontalBox = new QskLinearBox( Qt::Horizontal );
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horizontalBox->setPreferredSize( { 200, 75 } );
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QImage image1( ":/images/cloud.svg" );
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QskGraphic graphic1 = QskGraphic::fromImage( image1 );
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auto* label1 = new QskGraphicLabel( graphic1, horizontalBox );
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label1->setSizePolicy( QskSizePolicy::ConstrainedPreferred, QskSizePolicy::Expanding );
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QImage image2( ":/images/train.svg" );
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QskGraphic graphic2 = QskGraphic::fromImage( image2 );
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auto* label2 = new QskGraphicLabel( graphic2, horizontalBox );
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label2->setSizePolicy( QskSizePolicy::ConstrainedPreferred, QskSizePolicy::Expanding );
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...
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....
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.graphics with preferred size
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image::../images/scalable-graphics-1.png[Scalable graphics default]
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When resizing the window, the graphics will scale according to the size
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available in the layout:
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.graphics bounded by width
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image::../images/scalable-graphics-2.png[Scalable graphics bounded by width]
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.graphics bounded by height
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image::../images/scalable-graphics-3.png[Scalable graphics bounded by height]
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Since we set the horizontal size policy of the graphics to
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`ConstrainedPreferred`, the scaling is done through QskGraphic’s
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`widthForHeight()` methods to maintain the correct aspect ratio. If we
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had set the vertical policy to `ConstrainedPreferred` and the horizontal
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one to e.g. `Expanding`, the layout would have queried the
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`heightForWidth()` method instead.
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Of course non-scalable graphics like PNGs and JPGs are also supported:
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[source]
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....
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QImage image( "background.jpg" );
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QskGraphic graphic = QskGraphic::fromImage( image );
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...
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....
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