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.TH "tqvfb" "1" "3.0.3" "Troll Tech AS, Norway." ""
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.SH "NAME"
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.LP
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tqvfb \- Virtual framebuffer for Qt
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.SH "DESCRIPTION"
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.LP
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The virtual framebuffer allows Qt/Embedded programs to be
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developed on your desktop machine, without switching
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between consoles and X11.
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Start a Qt/Embedded master application (i.e., construct
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QApplication with QApplication::GuiServer flag or use the
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\-qws command line parameter). You will need to specify to
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the server that you wish to use the virtual framebuffer
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driver, e.g.:
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widgets \-qws \-display QVFb:0
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You may prefer to set the QWS_DISPLAY environment
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variable to be QVFb:0.
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tqvfb supports the following command line options:
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\-width width: the width of the virtual framebuffer
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(default: 240).
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\-height height: the height of the virtual framebuffer
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(default: 320).
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\-depth depth: the depth of the virtual framebuffer (1, 8
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or 32; default: 8).
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\-nocursor: do not display the X11 cursor in the
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framebuffer window.
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\-qwsdisplay :id the Qt/Embedded display id to provide
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(default: 0).
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Virtual Framebuffer Design
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The virtual framebuffer emulates a framebuffer using a
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shared memory region (the virtual frame buffer) and a
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utility to display the framebuffer in a window (tqvfb).
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The regions of the display that have changed are updated
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periodically, so you will see discrete snapshots of the
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framebuffer rather than each individual drawing
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operation. For this reason drawing problems such as
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flickering may not be apparent until the program is run
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using a real framebuffer.
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The target refresh rate can be set via the "View|Refresh
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Rate" menu item. This will cause tqvfb to check for
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updated regions more quickly. The rate is a target only.
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If little drawing is being done, the framebuffer will not
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show any updates between drawing events. If an
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application is displaying an animation the updates will
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be frequent, and the application and tqvfb will compete
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for processor time.
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Mouse and keyboard events are passed to the Qt/Embedded
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master process via named pipes.
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The virtual framebuffer is a development tool only. No
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security issues have been considered in the virtual
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framebuffer design. It should be avoided in a production
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environment; TQT_NO_QWS_VFB should always be defined in
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production libraries.
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.SH "AUTHORS"
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.LP
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TrollTech <http://www.trolltech.com/>
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