save/load qimage buffer using cache directory

Author: sulincix

src/tools.h

@@ -87,6 +87,9 @@ extern void setupWidgets();
 
 extern bool hasSelection;
 
+bool saveImageToFile(const QImage &image, const QString &imageFilePath);
+QImage loadImageFromFile(const QString &imageFilePath);
+
 extern void setupBackground();
 extern void setupScreenShot();
 extern void setupPenType();

src/tools/save-load.cpp

@@ -1,5 +1,8 @@
-#include "../tools.h"
+#include <QImage>
+#include <QByteArray>
+#include <QFile>
 
+#include "../tools.h"
 
 #ifdef LIBARCHIVE
 extern "C" {
@@ -83,3 +86,55 @@ void setupSaveLoad(){
     set_shortcut(toolButtons[OPEN], Qt::Key_O, Qt::ControlModifier);
 #endif
 }
+
+
+
+bool saveImageToFile(const QImage &image, const QString &imageFilePath) {
+    if (image.isNull()) {
+        return false;
+    }
+
+    QFile imageFile(imageFilePath);
+    if (!imageFile.open(QIODevice::WriteOnly)) {
+        return false;
+    }
+
+    QByteArray imageData(reinterpret_cast<const char*>(image.constBits()), image.sizeInBytes());
+    imageFile.write(imageData);
+    imageFile.close();
+
+    QFile dimensionsFile(imageFilePath+".dim");
+    if (!dimensionsFile.open(QIODevice::WriteOnly)) {
+        return false;
+    }
+
+    QDataStream out(&dimensionsFile);
+    out << image.width() << image.height() << static_cast<int>(image.format());
+    dimensionsFile.close();
+
+    return true;
+}
+QImage loadImageFromFile(const QString &imageFilePath) {
+    QFile dimensionsFile(imageFilePath+".dim");
+    if (!dimensionsFile.open(QIODevice::ReadOnly)) {
+        return QImage();
+    }
+
+    QDataStream in(&dimensionsFile);
+    int width, height, format;
+    in >> width >> height >> format;
+    dimensionsFile.close();
+
+    QFile imageFile(imageFilePath);
+    if (!imageFile.open(QIODevice::ReadOnly)) {
+        return QImage();
+    }
+
+    QByteArray loadedData = imageFile.readAll();
+    imageFile.close();
+
+    QImage loadedImage(reinterpret_cast<const uchar*>(loadedData.constData()), width, height, static_cast<QImage::Format>(format));
+    return loadedImage.copy();
+}
+
+

src/widgets/DrawingWidget.cpp

@@ -22,6 +22,7 @@ extern WhiteBoard *board;
 extern QWidget * mainWidget;
 extern DrawingWidget *drawing;
 extern FloatingSettings *floatingSettings;
+QString cache = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + "/pardus-pen/";
 
 extern void updateGoBackButtons();
 void removeDirectory(const QString &path);
@@ -108,7 +109,9 @@ class ImageStorage {
     int overlayType = BLANK;
     int removed = 0;
     void saveValue(qint64 id, QImage data) {
-        values[id] = data;
+        QDir dir;
+        dir.mkpath(cache_path);
+        saveImageToFile(data, cache_path+QString::number(id));
         updateGoBackButtons();
         if(id > history){
             remove(id - history);
@@ -117,19 +120,21 @@ class ImageStorage {
     }
 
     void clear(){
-        values.clear();
         image_count = 0;
         last_image_num = 1;
         removed = 0;
         updateGoBackButtons();
+        removeDirectory(cache_path);
     }
 
     QImage loadValue(qint64 id) {
         if(removed >= id) {
             id =  removed +1;
         }
-        if (values.contains(id)) {
-            return values[id];
+        QString filePath = cache_path+QString::number(id);
+        QFile file(filePath);
+        if(file.exists()){
+            return loadImageFromFile(cache_path+QString::number(id));
         } else {
             QImage image = QImage(mainWidget->geometry().width(),mainWidget->geometry().height(), QImage::Format_ARGB32);
             image.fill(QColor("transparent"));
@@ -138,16 +143,15 @@ class ImageStorage {
     }
 
     void remove(qint64 id){
-        for (auto it = values.begin(); it != values.end(); ++it) {
-            if (it.key() == id) {
-                values.erase(it);
-                break;
-            }
+        QString filePath = cache_path+QString::number(id);
+        QFile file(filePath);
+        if(file.exists()){
+            file.remove();
         }
     }
 
 private:
-    QMap<qint64, QImage> values;
+    QString cache_path = cache + generateRandomString(10)+"/";
 };
 ImageStorage images;
 
@@ -313,6 +317,7 @@ DrawingWidget::DrawingWidget(QWidget *parent): QWidget(parent) {
     fpressure = get_int((char*)"pressure") / 100.0;
 
     setFocusPolicy(Qt::StrongFocus);
+    removeDirectory(cache);
 }
 
 void DrawingWidget::addPoint(int id, QPointF data) {
@@ -725,3 +730,16 @@ void qImageToFile(const QImage& image, const QString& filename) {
         }
 }
 
+QString generateRandomString(int length) {
+    const QString characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+    QString randomString;
+
+    QRandomGenerator *generator = QRandomGenerator::global();
+    for (int i = 0; i < length; ++i) {
+        int index = generator->bounded(characters.length());
+        randomString.append(characters[index]);
+    }
+
+    return randomString;
+}
+

src/widgets/DrawingWidget.h

@@ -8,6 +8,7 @@
 #include <QMouseEvent>
 #include <QApplication>
 #include <QScreen>
+#include <QRandomGenerator>
 #include <iostream>
 
 #include <QtWidgets>
@@ -162,6 +163,7 @@ class DrawingWidget : public QWidget {
 
 QColor convertColor(QColor color);
 void qImageToFile(const QImage& image, const QString& filename);
+QString generateRandomString(int length);
 
 #endif // DRAWINGWIDGET_H