Implement the format conversion worker

Ignore the format file edit. Reformat after merge

.clang-format

@@ -1,4 +1,4 @@
-AccessModifierOffset: 0
+AccessModifierOffset: -4
 AlignEscapedNewlinesLeft: false
 AlignTrailingComments: true
 AllowAllParametersOfDeclarationOnNextLine: false
@@ -12,7 +12,7 @@ BreakBeforeBinaryOperators: true
 BreakBeforeBraces: Attach
 BreakBeforeTernaryOperators: false
 BreakConstructorInitializersBeforeComma: false
-ColumnLimit: 140
+ColumnLimit: 120
 CommentPragmas: ''
 ConstructorInitializerAllOnOneLineOrOnePerLine: false
 ConstructorInitializerIndentWidth: 0

KShare.pro

@@ -46,7 +46,8 @@ SOURCES += main.cpp\
     cropeditor/drawing/pathitem.cpp \
     cropeditor/drawing/lineitem.cpp \
     cropeditor/drawing/textitem.cpp \
-    colorpicker/colorpickerscene.cpp
+    colorpicker/colorpickerscene.cpp \
+    worker/worker.cpp
 
 HEADERS  += mainwindow.hpp \
     cropeditor/cropeditor.hpp \
@@ -74,7 +75,8 @@ HEADERS  += mainwindow.hpp \
     cropeditor/drawing/textitem.hpp \
     colorpicker/colorpickerscene.hpp \
     platformbackend.hpp \
-    gif-h/gif.h
+    gif-h/gif.h \
+    worker/worker.hpp
 
 mac {
         SOURCES += $$PWD/platformspecifics/mac/macbackend.cpp

main.cpp

@@ -3,28 +3,30 @@
 #include <QApplication>
 #include <QCommandLineParser>
 #include <QtGlobal>
+#include <iostream>
 #include <notifications.hpp>
 #include <stdio.h>
+#include <worker/worker.hpp>
 
 bool verbose = false;
 
 void handler(QtMsgType type, const QMessageLogContext &, const QString &msg) {
-    QByteArray localMsg = msg.toLocal8Bit();
+    std::string stdMsg = msg.toStdString();
     switch (type) {
     case QtDebugMsg:
-        if (verbose) fprintf(stdout, "DEBUG: %s\n", localMsg.constData());
+        if (verbose) std::cout << "DEBUG: " << stdMsg << "\n";
         break;
     case QtInfoMsg:
-        fprintf(stdout, "INFO: %s\n", localMsg.constData());
+        std::cout << "INFO: " << stdMsg << "\n";
         break;
     case QtWarningMsg:
-        fprintf(stderr, "WARN: %s\n", localMsg.constData());
+        std::cerr << "WARN: " << stdMsg << "\n";
         break;
     case QtCriticalMsg:
-        fprintf(stderr, "CRIT: %s\n", localMsg.constData());
+        std::cerr << "CRIT: " << stdMsg << "\n";
         break;
     case QtFatalMsg:
-        fprintf(stderr, "FATAL: %s\n", localMsg.constData());
+        std::cerr << "FATAL: " << stdMsg << "\n";
         notifications::notify("KShare Fatal Error", msg, QSystemTrayIcon::Critical);
         break;
     }
@@ -57,6 +59,7 @@ int main(int argc, char *argv[]) {
     verbose = parser.isSet(v);
 
     MainWindow w;
+    Worker::init();
     if (!parser.isSet(h)) w.show();
     return a.exec();
 }

worker/worker.cpp

@@ -0,0 +1,54 @@
+#include "worker.hpp"
+#include <chrono>
+#include <thread>
+
+Worker *Worker::inst = 0;
+QMutex Worker::workerLock;
+
+void Worker::queue(WorkerContext *context) {
+    QMutexLocker ml(&lock);
+    qqueue.enqueue(context);
+}
+
+void Worker::init() {
+    QMutexLocker ml(&workerLock);
+    if (!inst) inst = new Worker;
+}
+
+Worker::Worker() : QObject() {
+    thr = new QThread;
+    moveToThread(thr);
+    connect(thr, &QThread::started, this, &Worker::process);
+    connect(thr, &QThread::finished, thr, &QThread::deleteLater);
+    connect(this, &Worker::finished, thr, &QThread::quit);
+    connect(this, &Worker::finished, this, &Worker::deleteLater);
+    connect(thr, &QThread::finished, thr, &QThread::deleteLater);
+    thr->start();
+}
+
+Worker::~Worker() {
+    end();
+}
+
+void Worker::end() {
+    QMutexLocker ml(&endLock);
+    _ended = true;
+}
+
+bool Worker::ended() {
+    QMutexLocker ml(&endLock);
+    return _ended;
+}
+
+void Worker::process() {
+    while (!ended()) {
+        lock.lock();
+        if (!qqueue.isEmpty()) {
+            WorkerContext *c = qqueue.dequeue();
+            c->consumer(c->pixmap.toImage().convertToFormat(c->targetFormat));
+        }
+        lock.unlock();
+        std::this_thread::sleep_for(std::chrono::milliseconds(100)); // STL likes it's scopes
+    }
+    emit finished();
+}

worker/worker.hpp

@@ -0,0 +1,47 @@
+#ifndef WORKER_HPP
+#define WORKER_HPP
+
+#include <QImage>
+#include <QMutex>
+#include <QObject>
+#include <QPixmap>
+#include <QQueue>
+#include <QThread>
+#include <functional>
+
+struct WorkerContext {
+    QPixmap pixmap;
+    QImage::Format targetFormat;
+    std::function<void(QImage)> consumer;
+};
+
+class Worker : public QObject {
+    Q_OBJECT
+public:
+    void queue(WorkerContext *context);
+    static void init();
+
+private:
+    Worker();
+    ~Worker();
+    QMutex lock;
+    QMutex endLock;
+    QThread *thr;
+    QQueue<WorkerContext *> qqueue; // Say that ten times as fast
+    bool _ended;
+
+    void _queue(WorkerContext *context);
+    void end();
+    bool ended();
+
+    static Worker *inst;
+    static QMutex workerLock;
+signals:
+    void error(QString err);
+    void finished();
+
+public slots:
+    void process();
+};
+
+#endif // WORKER_HPP