Implement searching backwards

doc/katarakt.txt

@@ -91,9 +91,11 @@ KEY BINDINGS
 *[*, *]* ::
 	Adjust column count ('grid layout' only).
 */* ::
-	Show search bar. Hitting *Esc* will hide the results, searching for an
+	Show the search bar. Hitting *Esc* will hide the results, searching for an
 	empty string will clear them. If the search term contains an uppercase
 	letter the search is case sensitive ("smartcase").
+*?* ::
+	Show the search bar. This next search will be backwards.
 *n*, *N* ::
 	Focus next/previous search hit.
 *\^n*, *^N* ::

share/katarakt.ini

@@ -40,6 +40,7 @@ columns_dec=[
 toggle_overlay=T
 quit=Q, "W,E,E,E"
 search=/
+search_backward=?
 next_hit=N
 previous_hit=Shift+N
 next_invisible_hit=Ctrl+N

src/config.cpp

@@ -59,6 +59,7 @@ CFG::CFG() :
 	keys["toggle_overlay"] = QStringList() << "T";
 	keys["quit"] = QStringList() << "Q" << "W,E,E,E";
 	keys["search"] = QStringList() << "/";
+	keys["search_backward"] = QStringList() << "?";
 	keys["next_hit"] = QStringList() << "N";
 	keys["previous_hit"] = QStringList() << "Shift+N";
 	keys["next_invisible_hit"] = QStringList() << "Ctrl+N";

src/layout/layout.cpp

@@ -106,19 +106,34 @@ bool Layout::scroll_page(int new_page, bool relative) {
 
 void Layout::update_search() {
 	const map<int,QList<QRectF> *> *hits = viewer->get_search_bar()->get_hits();
+	if (hits->empty()) {
+		return;
+	}
 
+	// find the right page before/after the current one
 	map<int,QList<QRectF> *>::const_iterator it = hits->lower_bound(page);
-	if (it != hits->end()) {
-		hit_page = it->first;
-		hit_it = hits->find(hit_page)->second->begin();
-		view_hit();
+	bool forward = viewer->get_search_bar()->is_search_forward();
+	if (forward) {
+		if (it == hits->end()) {
+			it = hits->lower_bound(0);
+		}
 	} else {
-		if (hits->size() == 1) {
-			hit_page = hits->lower_bound(0)->first;
-			hit_it = hits->find(hit_page)->second->begin();
-			view_hit();
+		if (it->first != page) {
+			if (it == hits->begin()) {
+				it = hits->end();
+			}
+			--it;
 		}
 	}
+
+	hit_page = it->first;
+	if (forward) {
+		hit_it = it->second->begin();
+	} else {
+		hit_it = it->second->end();
+		--hit_it;
+	}
+	view_hit();
 }
 
 void Layout::set_search_visible(bool visible) {
@@ -132,7 +147,7 @@ bool Layout::advance_hit(bool forward) {
 		return false;
 	}
 	// find next hit
-	if (forward) {
+	if (forward ^ !viewer->get_search_bar()->is_search_forward()) {
 		++hit_it;
 		if (hit_it == hits->find(hit_page)->second->end()) {
 			// this was the last hit on hit_page

src/layout/presentationlayout.cpp

@@ -144,7 +144,7 @@ bool PresentationLayout::advance_invisible_hit(bool forward) {
 		return false;
 	}
 
-	if (forward) {
+	if (forward ^ !viewer->get_search_bar()->is_search_forward()) {
 		hit_it = hits->find(hit_page)->second->end();
 		--hit_it;
 	} else {

src/layout/presenterlayout.cpp

@@ -224,7 +224,7 @@ bool PresenterLayout::advance_invisible_hit(bool forward) {
 		return false;
 	}
 
-	if (forward) {
+	if (forward ^ !viewer->get_search_bar()->is_search_forward()) {
 		hit_it = hits->find(hit_page)->second->end();
 		--hit_it;
 	} else {

src/search.cpp

@@ -14,7 +14,8 @@ using namespace std;
 SearchWorker::SearchWorker(SearchBar *_bar) :
 		stop(false),
 		die(false),
-		bar(_bar) {
+		bar(_bar),
+		forward(true) {
 }
 
 void SearchWorker::run() {
@@ -36,6 +37,7 @@ void SearchWorker::run() {
 		}
 		int start = bar->start_page;
 		QString search_term = bar->term;
+		forward = bar->forward;
 		bar->term_mutex.unlock();
 
 		// check if term contains upper case letters; if so, do case sensitive search (smartcase)
@@ -101,16 +103,27 @@ void SearchWorker::run() {
 			}
 
 			// update progress label next to the search bar
-			int percent = ((page + bar->doc->numPages() - start)
-					% bar->doc->numPages()) * 100 / bar->doc->numPages();
+			int percent;
+			if (forward) {
+				percent = page + bar->doc->numPages() - start;
+			} else {
+				percent = start + bar->doc->numPages() - page;
+			}
+			percent = (percent % bar->doc->numPages()) * 100 / bar->doc->numPages();
 			QString progress = QString("[%1] %2\% searched, %3 hits")
 				.arg(has_upper_case ? "Case" : "no case")
 				.arg(percent)
 				.arg(hit_count);
 			emit update_label_text(progress);
 
-			if (++page == bar->doc->numPages()) {
-				page = 0;
+			if (forward) {
+				if (++page == bar->doc->numPages()) {
+					page = 0;
+				}
+			} else {
+				if (--page == -1) {
+					page = bar->doc->numPages() - 1;
+				}
 			}
 		} while (page != start);
 #ifdef DEBUG
@@ -199,7 +212,8 @@ bool SearchBar::is_valid() const {
 	return doc != NULL;
 }
 
-void SearchBar::focus() {
+void SearchBar::focus(bool forward) {
+	forward_tmp = forward; // only apply when the user presses enter
 	line->activateWindow();
 	line->setText(term);
 	line->setFocus(Qt::OtherFocusReason);
@@ -211,6 +225,10 @@ const std::map<int,QList<QRectF> *> *SearchBar::get_hits() const {
 	return &hits;
 }
 
+bool SearchBar::is_search_forward() const {
+	return forward;
+}
+
 bool SearchBar::event(QEvent *event) {
 	if (event->type() == QEvent::Hide) {
 		viewer->get_canvas()->set_search_visible(false);
@@ -261,6 +279,7 @@ void SearchBar::set_text() {
 		return;
 	}
 
+	forward = forward_tmp;
 	Canvas *c = viewer->get_canvas();
 	// do not start the same search again but signal slots
 	if (term == line->text()) {

src/search.h

@@ -36,6 +36,7 @@ signals:
 
 private:
 	SearchBar *bar;
+	bool forward;
 };
 
 
@@ -48,8 +49,9 @@ public:
 
 	void load(const QString &file, const QByteArray &password);
 	bool is_valid() const;
-	void focus();
+	void focus(bool forward = true);
 	const std::map<int,QList<QRectF> *> *get_hits() const;
+	bool is_search_forward() const;
 
 signals:
 	void search_updated(int page);
@@ -85,6 +87,8 @@ private:
 	SearchWorker *worker;
 	QString term;
 	int start_page;
+	bool forward_tmp;
+	bool forward;
 
 	friend class SearchWorker;
 };

src/viewer.cpp

@@ -345,6 +345,10 @@ void Viewer::search() {
 	search_bar->focus();
 }
 
+void Viewer::search_backward() {
+	search_bar->focus(false);
+}
+
 void Viewer::next_hit() {
 	if (canvas->get_layout()->get_search_visible()) {
 		int page = canvas->get_layout()->get_page();
@@ -510,6 +514,7 @@ void Viewer::setup_keys(QWidget *base) {
 	add_action(base, "columns_dec", SLOT(columns_dec()));
 	add_action(base, "quit", SLOT(quit()));
 	add_action(base, "search", SLOT(search()));
+	add_action(base, "search_backward", SLOT(search_backward()));
 	add_action(base, "next_hit", SLOT(next_hit()));
 	add_action(base, "previous_hit", SLOT(previous_hit()));
 	add_action(base, "next_invisible_hit", SLOT(next_invisible_hit()));

src/viewer.h

@@ -59,6 +59,7 @@ private slots:
 	void columns_dec();
 	void quit();
 	void search();
+	void search_backward();
 	void next_hit();
 	void previous_hit();
 	void next_invisible_hit();