How to use ProgressMonitor function of ImageMagick on iOS? - ios

Question

I am using Image Magick on ios and I have converted some command lines used on my server into a ConvertImageCommand. Everything work well.
I have added the -monitor as an argument to the command so I can see every tiny progress on my image (loading, resizing, cropping, etc)
However, I would like to display a progress bar to inform the user on the progress of the image process.
I am looking for a very simple example on how to use the progress monitor function...
SetImageProgressMonitor(Image *,const MagickProgressMonitor,void *),
SetImageInfoProgressMonitor(ImageInfo *,const MagickProgressMonitor,void *);
Can somebody help me ?

Answer 1

Here is the code:
- (void)ExecuteCommand {
/*
command is an array which contains all the elements of the ImageMagick command.
example:
command (
convert,
imgSource.jpg,
"-blur",
"0x2.5",
"-paint",
5,
imgSaved.jpg
)
*/
ImageInfo *imageInfo = AcquireImageInfo();
int nbArgs = command.count;
char **argv = (char **)malloc((nbArgs + 1) * sizeof(char*));
for (unsigned i = 0; i < nbArgs; i++)
{
NSString *argString = [command objectAtIndex:i];
argv[i] = strdup([argString UTF8String]);
}
argv[nbArgs] = NULL;
progress_monitor_method = SetImageInfoProgressMonitor(imageInfo, &MonitorProgress, self);
ConvertImageCommand(imageInfo, nbArgs, argv, NULL, AcquireExceptionInfo());
if (argv != NULL)
{
for (unsigned index = 0; argv[index] != NULL; index++) {
free(argv[index]);
}
free(argv);
}
}
MagickBooleanType MonitorProgress(const char *text,const MagickOffsetType offset,const MagickSizeType extent,void *client_data) {
IM_TestViewController *IMVC = client_data;
float prog = offset;
float tot = extent;
NSNumber *value = [NSNumber numberWithFloat:prog/tot];
[IMVC performSelectorInBackground:#selector(updateProgressBar:) withObject:value] ;
NSLog(#"Action : %# %lld on %lld", [NSString stringWithCString:text encoding:NSUTF8StringEncoding], offset, extent);
return MagickTrue;
}
- (void)updateProgressBar:(NSNumber *)value {
self.progressBar.progress = [value floatValue];
}