I want to build an app to scan QRCode and Barcode. I want to use camera scan image contains the code (QRCode or BarCode) but not take photo. Now I have no idea to do it. Anyone, give some references, please!
You should look at: http://zbar.sourceforge.net/
Download the ZBarSDK and import it in pch file then use this code
// BarCodeView.h
#interface BarCodeView : UIViewController < ZBarReaderDelegate > {
UIImageView *resultImage;
UITextView *resultText;
}
#property (nonatomic, retain) IBOutlet UIImageView *resultImage;
#property (nonatomic, retain) IBOutlet UITextView *resultText;
- (IBAction) scanButtonTapped;
// BarCodeView.m
#synthesize resultImage, resultText;
- (IBAction) scanButtonTapped
{
NSLog(#"TBD: scan barcode here...");
// ADD: present a barcode reader that scans from the camera feed
ZBarReaderViewController *reader = [ZBarReaderViewController new];
reader.readerDelegate = self;
reader.supportedOrientationsMask = ZBarOrientationMaskAll;
ZBarImageScanner *scanner = reader.scanner;
// TODO: (optional) additional reader configuration here
// EXAMPLE: disable rarely used I2/5 to improve performance
[scanner setSymbology: ZBAR_I25
config: ZBAR_CFG_ENABLE
to: 0];
// present and release the controller
[self presentModalViewController: reader
animated: YES];
[reader release];
}
- (void) imagePickerController: (UIImagePickerController*) reader didFinishPickingMediaWithInfo: (NSDictionary*) info
{
// ADD: get the decode results
id<NSFastEnumeration> results =
[info objectForKey: ZBarReaderControllerResults];
ZBarSymbol *symbol = nil;
for(symbol in results)
// EXAMPLE: just grab the first barcode
break;
// EXAMPLE: do something useful with the barcode data
resultText.text = symbol.data;
// EXAMPLE: do something useful with the barcode image
resultImage.image =
[info objectForKey: UIImagePickerControllerOriginalImage];
// ADD: dismiss the controller (NB dismiss from the *reader*!)
[reader dismissModalViewControllerAnimated: YES];
}
The two most active projects are ZBar and ZXing.
You didn't mention if you were targeting iOS or OS X. I don't believe ZBar suports OS X. ZXing does. I believe ZBar has better support for 1D codes than the C++-based ports of ZXing.
(FWIW, I'm an active contributor to the C++/OS X/iOS port of ZXing.)
Related
Newbie here. I'm trying to create a small listener for application launches, and I already have this:
// almon.m
#import <Cocoa/Cocoa.h>
#import <stdio.h>
#include <signal.h>
#interface almon: NSObject {}
-(id) init;
-(void) launchedApp: (NSNotification*) notification;
#end
#implementation almon
-(id) init {
NSNotificationCenter * notify
= [[NSWorkspace sharedWorkspace] notificationCenter];
[notify addObserver: self
selector: #selector(launchedApp:)
name: #"NSWorkspaceWillLaunchApplicationNotification"
object: nil
];
fprintf(stderr,"Listening...\n");
[[NSRunLoop currentRunLoop] run];
fprintf(stderr,"Stopping...\n");
return self;
}
-(void) launchedApp: (NSNotification*) notification {
NSDictionary *userInfo = [notification userInfo]; // read full application launch info
NSString* AppPID = [userInfo objectForKey:#"NSApplicationProcessIdentifier"]; // parse for AppPID
int killPID = [AppPID intValue]; // define integer from NSString
kill((killPID), SIGSTOP); // interrupt app launch
NSString* AppPath = [userInfo objectForKey:#"NSApplicationPath"]; // read application path
NSString* AppBundleID = [userInfo objectForKey:#"NSApplicationBundleIdentifier"]; // read BundleID
NSString* AppName = [userInfo objectForKey:#"NSApplicationName"]; // read AppName
NSLog(#":::%#:::%#:::%#:::%#", AppPID, AppPath, AppBundleID, AppName);
}
#end
int main( int argc, char ** argv) {
[[almon alloc] init];
return 0;
}
// build: gcc -Wall almon.m -o almon -lobjc -framework Cocoa
// run: ./almon
Note: when I build it, it will run fine, but if you do it with Xcode 10 on High Sierra, you will get ld warnings, which you can ignore, however.
My question: Is there a way to also detect a launch of a background application, e.g. a menu bar application like Viscosity etc.? Apple says that
the system does not post
[NSWorkspaceWillLaunchApplicationNotification] for background apps or
for apps that have the LSUIElement key in their Info.plist file.
If you want to know when all apps (including background apps) are
launched or terminated, use key-value observing to monitor the value
returned by the runningApplications method.
Here: https://developer.apple.com/documentation/appkit/nsworkspacewilllaunchapplicationnotification?language=objc
I would at least try to add support for background apps etc. to the listener, but I don't know how to go about it. Any ideas?
As the document suggests, you use Key-Value Observing to observe the runningApplications property of the shared workspace object:
static const void *kMyKVOContext = (void*)&kMyKVOContext;
[[NSWorkspace sharedWorkspace] addObserver:self
forKeyPath:#"runningApplications"
options:NSKeyValueObservingOptionNew // maybe | NSKeyValueObservingOptionInitial
context:kMyKVOContext];
Then, you would implement the observation method (using Xcode's ready-made snippet):
- (void) observeValueForKeyPath:(NSString*)keyPath ofObject:(id)object change:(NSDictionary*)change context:(void*)context
{
if (context != kMyKVOContext)
{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
return;
}
if ([keyPath isEqualToString:#"runningApplications"])
{
<#code to be executed when runningApplications has changed#>
}
}
I have a memory leak that I cannot diagnose. I have tried multiple approaches to creating a seamlessly looped video - Besides AVPlayerLooper, all of the approaches I've encountered and tried involve creating an observer to watch AVPlayerItemDidPlayToEndTimeNotification and then either seeking to the beginning of the video (in the case of AVPlayer) or inserting the video to be looped into the video queue (in the case of AVQueuePlayer). Both seem to have similar performance, but both also have a consistent memory keep related to the seekToTime method (in the case of AVPlayer) and the insertItem method (in the case of AVQueuePlayer). My end goal is to create a subclass of SKVideoNode that loops by default. Below is my code for the subclass:
#import "SDLoopingVideoNode.h"
#import <AVFoundation/AVFoundation.h>
#interface SDLoopingVideoNode()
#property AVQueuePlayer *avQueuePlayer;
#property AVPlayerLooper *playerLooper;
#end
#implementation SDLoopingVideoNode
-(instancetype)initWithPathToResource:(NSString *)path withFiletype:(NSString *)filetype
{
if(self == [super init])
{
NSString *resourcePath = [[NSBundle mainBundle] pathForResource:path ofType:filetype];
NSURL *videoURL = [NSURL fileURLWithPath:resourcePath];
AVAsset *videoAsset = [AVAsset assetWithURL:videoURL];
AVPlayerItem * videoItem = [AVPlayerItem playerItemWithAsset:videoAsset];
self.avQueuePlayer = [[AVQueuePlayer alloc] initWithItems:#[videoItem]];
NSNotificationCenter *noteCenter = [NSNotificationCenter defaultCenter];
[noteCenter addObserverForName:AVPlayerItemDidPlayToEndTimeNotification
object:nil
queue:nil
usingBlock:^(NSNotification *note) {
AVPlayerItem *video = [[AVPlayerItem alloc] initWithURL:videoURL];
[self.avQueuePlayer insertItem:video afterItem:nil];
NSLog(#"Video changed");
}];
self = (SDLoopingVideoNode*)[[SKVideoNode alloc] initWithAVPlayer: self.avQueuePlayer];
return self;
}
return nil;
}
#end
And here is how the subclass is initialized in didMoveToView:
SDLoopingVideoNode *videoNode = [[SDLoopingVideoNode alloc]initWithPathToResource:#"147406" withFiletype:#"mp4"];
[videoNode setSize:CGSizeMake(self.size.width, self.size.height)];
[videoNode setAnchorPoint:CGPointMake(0.5, 0.5)];
[videoNode setPosition:CGPointMake(0, 0)];
[self addChild:videoNode];
[videoNode play];
Short answer is, you will not be able to get that working with AVPlayer. Believe me, I have tried. Instead, it is possible to do seamless looping by using the H264 hardware to decode and then re-encode each video frame as a keyframe, github link here. I have also built a seamless looping layer that supports a full alpha channel. Performance even for full screen 1x1 video on and iPad or iPad pro is great. Also, no memory leaks with this code.
Apple demoed this code in their WWDC 2014 Session 608 video on best practices for SpriteKit.
AppDelegate.m
+ (instancetype)unarchiveFromFile:(NSString *)file {
/* Retrieve scene file path from the application bundle */
NSString *nodePath = [[NSBundle mainBundle] pathForResource:file ofType:#"sks"];
/* Unarchive the file to an SKScene object */
NSData *data = [NSData dataWithContentsOfFile:nodePath
options:NSDataReadingMappedIfSafe
error:nil];
NSKeyedUnarchiver *arch = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
[arch setClass:self forClassName:#"SKScene"];
SKScene *scene = [arch decodeObjectForKey:NSKeyedArchiveRootObjectKey];
[arch finishDecoding];
return scene;
}
I understand the gist of what it's doing, but what I'm confused about is how to utilize this code in for any other .sks file. I tried calling the unarchiveFromFile method from my GameScene.m class, but to no avail. I read the post here on this topic, but it did not clarify things.
EDIT
As per what was suggested by Okapi, I tried the following in a new OS X SceneKit project in the GameScene.m class:
#import "GameScene.h"
#implementation GameScene
-(void)didMoveToView:(SKView *)view {
SKNode *nodeInScene2 = [self childNodeWithName:#"object1"];
for (SKNode *blah in [SKScene unarchiveFromFile:#"Scene2"].children) {
[nodeInScene2 addChild:blah];
}
}
-(void)update:(CFTimeInterval)currentTime {
/* Called before each frame is rendered */
}
#end
I have 2 .sks files. The first is called GameScene.sks and that has a sprite in there called "object1". I would like to add children stored in "Scene2.sks". The loop in the didMoveToView method gives me an error. What am I doing wrong? This is what Apple did in their WWDC 608 video, but perhaps I'm missing something since I can't find their project online.
+unarchiveFromFile: is defined as a category on SKScene in GameViewController.m. You would need to copy that code if you want to use it somewhere else.
#implementation SKScene (Unarchive)
+ (instancetype)unarchiveFromFile:(NSString *)file {
/* Retrieve scene file path from the application bundle */
NSString *nodePath = [[NSBundle mainBundle] pathForResource:file ofType:#"sks"];
/* Unarchive the file to an SKScene object */
NSData *data = [NSData dataWithContentsOfFile:nodePath
options:NSDataReadingMappedIfSafe
error:nil];
NSKeyedUnarchiver *arch = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
[arch setClass:self forClassName:#"SKScene"];
SKScene *scene = [arch decodeObjectForKey:NSKeyedArchiveRootObjectKey];
[arch finishDecoding];
return scene;
}
#end
This one hung me up for a while too. I ended up declaring unarchiveFromFile in every subclass that needed it, then calling it when I wanted to transition scenes. Something like this...
if (contactQuery == (playerCategory | proceedCategory)) {
SKScene *levelTwo = [LevelTwo unarchiveFromFile:#"LevelTwo"];
[self.view presentScene:levelTwo transition:[SKTransition doorsCloseHorizontalWithDuration:0.5]];
}
Full sample code can be downloaded here.
I am building a simple step sequencer in IRTcmix (version of RTcmix for the iphone/ipad), using UI Buttons to control which notes are on or off in the sequence.
I have been working with a set of RTcmix examples of other apps, and trying to piece my own together, but i'm unsure how to change values of a variable within the .sco (score file) with a toggle-style UIButton.
Here are some snippets from a working RTcmix App:
From the RTcmix manager .h:
#interface RTcmixManager : RTcmixPlayer {
RTcmixScore *polyScore;
}
#property (nonatomic, retain) RTcmixScore *polyScore;
- (void)noteOn:(int)note;
- (void)noteOff:(int)note;
#end
and the RTcmix manager .m
- (void)noteOn:(int)note {
[polyScore.mainScoreParameters replaceObjectAtIndex:0 withObject:[NSNumber numberWithInt:note]];
[polyScore.mainScoreParameters replaceObjectAtIndex:1 withObject:[NSNumber numberWithInt:1]];
[self parseScoreWithRTcmixScore:polyScore];
polyScore.setupIsActive = YES;
}
- (void)noteOff:(int)note {
[polyScore.mainScoreParameters replaceObjectAtIndex:0 withObject:[NSNumber numberWithInt:note]];
[polyScore.mainScoreParameters replaceObjectAtIndex:1 withObject:[NSNumber numberWithInt:0]];
[self parseScoreWithRTcmixScore:polyScore];
}
the viewcontroller .h:
#interface RTPolyphonyViewController : UIViewController {
RTcmixManager *rtcmixManager;
}
- (IBAction)keyDown:(UIButton *)sender;
- (IBAction)keyUp:(UIButton *)sender;
#end
viewcontroller .m:
- (IBAction)keyDown:(UIButton *)sender {
[rtcmixManager noteOn:sender.tag];
}
- (IBAction)keyUp:(UIButton *)sender {
[rtcmixManager noteOff:sender.tag];
}
and a snippet from the .sco file (the "%#" is the variables changed by user input):
NoteNumber = %#
NoteVelocity = %#
alreadySounding = note_exists(oscNotes[NoteNumber])
MAXMESSAGE(0, alreadySounding)
I am very new to objective C and xcode, I was wondering how to make a UI button toggle between two values in the score file (acting like a switch) for example, a button when toggled making the value of NoteNumber(in the score file) set to 1, while the value is 0 when toggled off. Because I am a beginner with Xcode(and objective C), I'm not sure about the proper syntax for making a button able to be toggled on and off, and i am also not sure how to connect said button with my .sco file, as much as I look at the sample code, I cannot seem to figure out how they all connect.
I have XCODE 3.1.4 running ona mini MAC 10.5.8 and Simulator 3.1
I want to send a short UDP string for some remote control and have made the following code
Basicly it does compile and run in the simulator ... but it nevers send any UDP to the target. I hope someone can give me a clue why it does not work
My .H code
#import <UIKit/UIKit.h>
#import "AsyncUdpSocket.h"
#import "AsyncSocket.h"
#interface ChangeLabelViewController : UIViewController {
IBOutlet UILabel *label ;
AsyncUdpSocket *socket;
}
-(IBAction) ChangeLabel;
-(IBAction) ResetLabel;
#end
My .m code
#import "ChangeLabelViewController.h"
#implementation ChangeLabelViewController
-(IBAction) ChangeLabel
{
label.text = #"Hello";
}
-(IBAction) ResetLabel
{
label.text = #"Empty";
NSLog(#"%s", __PRETTY_FUNCTION__);
NSString * string = #"Testing iPhone";
NSString * address = #"192.168.1.11";
UInt16 port = 1234;
NSData * data = [string dataUsingEncoding: NSUTF8StringEncoding];
if ([socket sendData:data toHost:address port:port withTimeout:- 1 tag:1]) label.text = #"Send";
// if ([socket sendData:data toHost:address port:port withTimeout:-1 tag:1] == YES) label.text = #"Yes";
// if ([socket sendData:data toHost:address port:port withTimeout:-1 tag:1] == NO) then label.text = #"No";
;
}
#end
Had to init the socket
under - (void) vievDidLoad
socket = [[AsyncUdpSocket alloc] initWithDelegate:self];
Then it worked as expected :-)
If you are staring from a brand new project you will also need to do the following:
1. add CFNetwork to your frameworks in the project
2. add the cocaasyncsockets files to your project
Instructions are here: http://code.google.com/p/cocoaasyncsocket/wiki/iPhone
Pay attention to the instructions on how to add CFNetwork, it is not shown in the list of available options.
Hint: you will need to use the finder to select a path, I am a mac novice so it took me a while to figure out that I had to use Go/Go To Folder....