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GUI coding. A peek at run-time inheritance (method lookups)

Posted 04-20-2012 at 08:23 AM by rainbowsally
Updated 04-20-2012 at 08:26 AM by rainbowsally

GUI coding. A peek at run-time inheritance (method lookups)

In previous blog entries we built QT's example/desktop/screenshot application and did a bit of tracing with a debugger.

Let's take a look at the metaobject definition file (moc_screenshot.cpp) next.

This is where QT implements a class' method inheritance. It looks up 'methods' from the widget's parent first, then if parent doesn't handle the '_id' we try it here, and if we don't handle it...

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New digital tune / gFifteen version 1.0

Posted 04-20-2012 at 01:34 AM by hydraMax (Bits and Pixels)

I finally was able to get a power adapter for my old CASIO keyboard, plus a MIDI adapter. With that and some RG editing I was able to produce this little tune:

https://frigidcode.com/digital-music/m05/m05.ogg (Ogg Vorbis)
https://frigidcode.com/digital-music/m05/m05.mp3 (Mp3)

*****

This is somewhat old news, but I should mention that gFifteen version 1.0 is available, with three additional tile sets for variety. Debian packages are available for...

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Master Command history in Linux Bash

Posted 04-19-2012 at 07:16 PM by stretchedthin
Updated 04-19-2012 at 08:35 PM by stretchedthin

Before you learn any commands in Linux, get to know how you can make the most of the history functions in Bash. This will save you and your fingers a lot of wear and tear. Learning this and making sure your working in a terminal emulator that has good copy past functionality and your going to find the command line a pretty comfortable place.
Master Command history in Linux Bash

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Cut and paste

Posted 04-19-2012 at 04:57 PM by peonuser
Updated 04-19-2012 at 05:32 PM by peonuser (typos)

The "legacy os" people pride themselves in how they support pentium 3 and pentium 4 systems. Funny. We still use linux on pentium I and pentium II machines.

Thanx to all the people who have viewed http://www.instructables.com/member/computothought/. Over 236,000 views now.

Trying to think of a super simple example of cut and paste for a class. Here is what I came up with:

Play pretend here for a second. You are a new accountant for a company...

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GUI coding. The 4 main parts of a typical GUI toolkit

Posted 04-19-2012 at 01:34 PM by rainbowsally
Updated 04-19-2012 at 01:51 PM by rainbowsally (clarification of 'metaobject' purpose in last line)

Tags compiling, computer mad science

Let's start slow.

First of all, most of the GUI toolkits including QT4 are set up in the following steps, and in this order.

Create an application, possibly with commandline args. (If not created explicitly this 'application' thing will already exist somewhere.)
Create a main widget with the 'application' thingie as its parent.
Show the main widget.
Run the application event loop.

The 'application' is the main event dispatcher which translates X events...

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