Implement toggleable color inversion ('i' key)

doc/katarakt.txt

@@ -91,6 +91,8 @@ KEY BINDINGS
 	Rotate pages left/right
 *\^o*, *^i*, *Alt-Left*, *Alt-Right* ::
 	Move backward/forward through the jump list. Entries are added automatically when jumping
+*i* ::
+	Toggle between normal and inverted color rendering
 
 VARIABLES
 ---------

share/katarakt.ini

@@ -49,6 +49,7 @@ rotate_left=,
 rotate_right=.
 jump_back=Ctrl+O, Alt+Left
 jump_forward=Ctrl+I, Alt+Right
+toggle_invert_colors=I
 toggle_fullscreen=F
 close_search=Esc
 reload=R

src/canvas.cpp

@@ -84,6 +84,7 @@ Canvas::Canvas(Viewer *v, QWidget *parent) :
 	add_action("rotate_right", SLOT(rotate_right()));
 	add_action("jump_back", SLOT(jump_back()));
 	add_action("jump_forward", SLOT(jump_forward()));
+	add_action("toggle_invert_colors", SLOT(invert_colors()));
 
 	// prints the string representation of a key
 //	cerr << QKeySequence(Qt::Key_Equal).toString().toUtf8().constData() << endl;
@@ -169,6 +170,11 @@ void Canvas::jump_forward() {
 	}
 }
 
+void Canvas::invert_colors() {
+	viewer->get_res()->invert_colors();
+	update();
+}
+
 Layout *Canvas::get_layout() const {
 	return cur_layout;
 }

src/canvas.h

@@ -81,6 +81,7 @@ private slots:
 	void rotate_right();
 	void jump_back();
 	void jump_forward();
+	void invert_colors();
 
 private:
 	void add_action(const char *action, const char *slot);

src/config.cpp

@@ -68,6 +68,7 @@ CFG::CFG() :
 	keys["rotate_right"] = QStringList() << ".";
 	keys["jump_back"] = QStringList() << "Ctrl+O" << "Alt+Left";
 	keys["jump_forward"] = QStringList() << "Ctrl+I" << "Alt+Right";
+	keys["toggle_invert_colors"] = QStringList() << "i";
 	// viewer keys
 	keys["toggle_fullscreen"] = QStringList() << "F";
 	keys["close_search"] = QStringList() << "Esc";

src/resourcemanager.cpp

@@ -10,7 +10,8 @@ using namespace std;
 
 //==[ Katarakt Page ]==========================================================
 KPage::KPage() :
-		links(NULL) {
+		links(NULL),
+		inverted_colors(false) {
 	for (int i = 0; i < 3; i++) {
 		status[i] = 0;
 		rotation[i] = 0;
@@ -138,11 +139,25 @@ void Worker::run() {
 			continue;
 		}
 
+		// invert to current color setting
+		if (res->inverted_colors) {
+			img.invertPixels();
+		}
+
 		// put page
 		res->k_page[page].mutex.lock();
 		if (!res->k_page[page].img[index].isNull()) {
 			res->k_page[page].img[index] = QImage(); // assign null image
 		}
+
+		// adjust all available images to current color setting
+		if (res->k_page[page].inverted_colors != res->inverted_colors) {
+			res->k_page[page].inverted_colors = res->inverted_colors;
+			for (int i = 0; i < 3; i++) {
+				res->k_page[page].img[i].invertPixels();
+			}
+			res->k_page[page].thumbnail.invertPixels();
+		}
 		res->k_page[page].img[index] = img;
 		res->k_page[page].status[index] = width;
 		res->k_page[page].rotation[index] = rotation;
@@ -182,7 +197,8 @@ void Worker::run() {
 ResourceManager::ResourceManager(QString file) :
 		doc(NULL),
 		center_page(0),
-		rotation(0) {
+		rotation(0),
+		inverted_colors(false) {
 	// load config options
 	CFG *config = CFG::get_instance();
 	smooth_downscaling = config->get_value("smooth_downscaling").toBool();
@@ -305,6 +321,13 @@ const KPage *ResourceManager::get_page(int page, int width, int index) {
 			k_page[page].rotation[index] != rotation) {
 		enqueue(page, width, index);
 	}
+	if (inverted_colors != k_page[page].inverted_colors) {
+		k_page[page].inverted_colors = inverted_colors;
+		for (int i = 0; i < 3; i++) {
+			k_page[page].img[i].invertPixels();
+		}
+		k_page[page].thumbnail.invertPixels();
+	}
 	return &k_page[page];
 }
 
@@ -334,6 +357,7 @@ void ResourceManager::collect_garbage(int keep_min, int keep_max) {
 			// find the index of the rendered image
 			for (int i = 0; i < 3; i++) {
 				if (!k_page[page].img[i].isNull()) {
+//					k_page[page].inverted_colors = inverted_colors;
 					// scale
 					k_page[page].thumbnail = k_page[page].img[i].scaled(
 							QSize(thumbnail_size, thumbnail_size),
@@ -391,6 +415,10 @@ void ResourceManager::unlock_page(int page) const {
 	k_page[page].mutex.unlock();
 }
 
+void ResourceManager::invert_colors() {
+	inverted_colors = !inverted_colors;
+}
+
 void ResourceManager::enqueue(int page, int width, int index) {
 	requestMutex.lock();
 	map<int,pair<int,int> >::iterator it = requests.find(page);

src/resourcemanager.h

@@ -36,6 +36,7 @@ private:
 	QMutex mutex;
 	int status[3];
 	char rotation[3];
+	bool inverted_colors; // img[]s and thumb must be consistent
 
 	friend class Worker;
 	friend class ResourceManager;
@@ -86,6 +87,7 @@ public:
 	int get_rotation() const;
 	void rotate(int value, bool relative = true);
 	void unlock_page(int page) const;
+	void invert_colors();
 
 	void collect_garbage(int keep_min, int keep_max);
 
@@ -123,6 +125,7 @@ private:
 	// config options
 	bool smooth_downscaling;
 	int thumbnail_size;
+	bool inverted_colors;
 };
 
 #endif