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Handle segmentation faults in try-catch block

Posted 05-06-2012 at 12:52 AM by rainbowsally
Updated 05-06-2012 at 05:19 AM by rainbowsally (updated code for 32 and also 64 bit arch)

Tags catching sigsegv, compiling, computer mad science, try-catch seg violations

[CHANGELOG:
May 6, 2012 (second edit)
Latest:
Tested 64 bit code (and also 32), corrected close brace in function that got lost in the #if-#else-#endif mixup (with extern "C" close brace)... nevermind. It works now.

Features:

catch segmentation faults and continue normally

Don't underestimate this concept. We'll be using it in the GUI-Interactive interpreter.

This is a highly simplified version of the SEH for linux experiment posted...

rainbowsally

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GUI-Interactive: Display a list of QT4 classes

Posted 05-05-2012 at 04:51 AM by rainbowsally
Updated 05-05-2012 at 05:00 AM by rainbowsally

Tags compiling, computer mad science

Today's features:

A stand alone executable to list all of QT4's classes.
A first function for an interactive interpreter for QT funcs and classes
Another simple but interesting parse job.

Requres:

the libLQ download (or your own work-alike hack)

http://www.linuxquestions.org/questi...eration-34648/

We are delving into QT's system for reasons explained in earlier blog entries. When I tried early...

rainbowsally

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QT4 Event preemption: mouse click to get object name

Posted 05-03-2012 at 11:30 AM by rainbowsally
Updated 08-06-2014 at 10:15 AM by rainbowsally

Tags compiling, computer mad science

See also the experiment to dump properties.
http://www.linuxquestions.org/questi...nal-app-34716/

Now that we have event preemption ability, let's get simple again and create ui application that can tell the name of a widget by clicking on it.

[It's simpler than you think but I have uploaded the sources and makefile in case my description of this process is too complicated or confusing.]
...

rainbowsally

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GUI Programming: QT4 Event Preeption Part 2-B (temp)

Posted 05-02-2012 at 08:38 PM by rainbowsally

Tags compiling, computer mad science

Here's the code to run the examples and create a subclass of QApplication customized for our event preeption test. (See part 2-A)

file: src/utils.h

Code:

// utils.h

#ifndef utils_h
#define utils_h

#include <QObject>

// See explanation in utils.cpp
int lq_hash32(const char* name);

// See explanation in utils.cpp
typedef struct 
{
  int hashid; // computed once
  const

...

rainbowsally

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GUI Programming: QT4 Event Preeption Part 2-A (temp)

Posted 05-02-2012 at 08:32 PM by rainbowsally
Updated 05-04-2012 at 11:33 AM by rainbowsally (QA check failed ;-))

Tags compiling, computer mad science

[Corrected hash algorithm to return -1 for null string (aka "") input. May 4, 2012]

Today's features

conditional compilation (OLD_SCHOOL vs. ?)
discovery of a potential recursion problem in preemptive event handling (QTextEdit)

This example is complicated enough to be but actually is not quite ready for prime time, but I do want to point out the advantage of creating hash values for speeding up text searches in tables of data. See the utils.cpp implementation...

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