×
Namespaces

Variants
Actions

Archived:Transparent QPixmap picture

From Nokia Developer Wiki
Jump to: navigation, search

Archived.pngArchived: This article is archived because it is not considered relevant for third-party developers creating commercial solutions today. If you think this article is still relevant, let us know by adding the template {{ReviewForRemovalFromArchive|user=~~~~|write your reason here}}.

Qt Quick should be used for all UI development on mobile devices. The approach described in this article (using C++ for the Qt app UI) is deprecated.

Article Metadata
Tested with
Devices(s): Nokia 5800 XpressMusic, Nokia N900
Compatibility
Platform(s): Qt
Symbian
Article
Keywords: QPixmap, QPainter
Created: tepaa (21 Oct 2009)
Last edited: hamishwillee (11 Oct 2012)

Contents

Overview

This example shows how to change a QPixmap picture to transparent.


Preconditions

  • Qt is installed on your platform.


Header

private:
// Original pixmap
QPixmap pixmap;


Source

// Create new picture for transparent
QPixmap transparent(pixmap.size());
 
// Do transparency
transparent.fill(Qt::transparent);
QPainter p(&transparent);
p.setCompositionMode(QPainter::CompositionMode_Source);
p.drawPixmap(0, 0, pixmap);
p.setCompositionMode(QPainter::CompositionMode_DestinationIn);
// Set transparency level to 150 (possible values are 0-255)
// The alpha channel of a color specifies the transparency effect,
// 0 represents a fully transparent color, while 255 represents
// a fully opaque color.
p.fillRect(transparent.rect(), QColor(0, 0, 0, 150));
p.end();
 
// Set original picture's reference to new transparent one
pixmap = transparent;


Postconditions

The picture is now transparent.


See also

This page was last modified on 11 October 2012, at 04:15.
138 page views in the last 30 days.

Was this page helpful?

Your feedback about this content is important. Let us know what you think.

 

Thank you!

We appreciate your feedback.

×