various improvements

ui/labelslider.cpp

@@ -10,7 +10,9 @@
 #include <QApplication>
 
 LabelSlider::LabelSlider(QWidget* parent) : QLabel(parent) {
+    // set a default frame rate - fallback, shouldn't ever really be used
 	frame_rate = 30;
+
 	decimal_places = 1;
 	drag_start = false;
 	drag_proc = false;
@@ -96,7 +98,7 @@ void LabelSlider::set_default_value(double v) {
 }
 
 void LabelSlider::set_minimum_value(double v) {
-	min_value = v;
+    min_value = v;
 	min_enabled = true;
 }
 
@@ -106,47 +108,102 @@ void LabelSlider::set_maximum_value(double v) {
 }
 
 void LabelSlider::mousePressEvent(QMouseEvent *ev) {
+    // if primary button is clicked
     if (ev->button() == Qt::LeftButton) {
+
+        // store initial value to be compared while dragging
 		drag_start_value = internal_value;
-		if (ev->modifiers() & Qt::AltModifier) {
+
+        // alt + click sets labelslider to default value
+		if (ev->modifiers() & Qt::AltModifier) {            
+
+            // if the value is not already default, and there is a default to set
 			if (internal_value != default_value && !qIsNaN(default_value)) {
+
+                // cache current value
 				set_previous_value();
+
+                // set back to default
 				set_value(default_value, true);
+
 			}
+
 		} else {
+
+            // if value isn't valid, we set to a "default" of 0
 			if (qIsNaN(internal_value)) internal_value = 0;
 
+            // hide the cursor and store information about it for dragging
 			qApp->setOverrideCursor(Qt::BlankCursor);
 			drag_start = true;
 			drag_start_x = cursor().pos().x();
 			drag_start_y = cursor().pos().y();
 		}
+
 		emit clicked();
-	}
+
+    } else {
+
+        // handler if the user clicks with a non-primary button
+        // prevents mouse from getting stuck in "dragging" mode
+        mouseReleaseEvent(ev);
+
+    }
 }
 
 void LabelSlider::mouseMoveEvent(QMouseEvent* event) {
 	if (drag_start) {
+        // if we're dragging
+
+        // we don't actually start fully dragging until the cursor has moved
+        // while the mouse is down, this helps prevent accidental drags
 		drag_proc = true;
+
+        // get amount cursor moved by
 		double diff = (cursor().pos().x()-drag_start_x) + (drag_start_y-cursor().pos().y());
+
+        // ctrl + drag drags in smaller increments
 		if (event->modifiers() & Qt::ControlModifier) diff *= 0.01;
+
+        // we'll also need to drag in smaller increments for a percent value
 		if (display_type == LABELSLIDER_PERCENT) diff *= 0.01;
+
+        // sets the value
 		set_value(internal_value + diff, true);
+
+        // keep the cursor in the same location while dragging
 		cursor().setPos(drag_start_x, drag_start_y);
 	}
 }
 
-void LabelSlider::mouseReleaseEvent(QMouseEvent* ev) {
+void LabelSlider::mouseReleaseEvent(QMouseEvent*) {
     if (drag_start) {
+
+        // unhide cursor
 		qApp->restoreOverrideCursor();
+
 		drag_start = false;
-		if (drag_proc) {
+
+        if (drag_proc) {
+            // if we just finished fully dragging
+
 			drag_proc = false;
+
 			previous_value = drag_start_value;
+
 			emit valueChanged();
+
 		} else {
+
+            // if the user didn't actually drag, and just clicked in one place,
+            // we instead present a dialog prompt for the user to enter a
+            // specific value
+
 			double d = internal_value;
-			if (display_type == LABELSLIDER_FRAMENUMBER) {
+
+            if (display_type == LABELSLIDER_FRAMENUMBER) {
+
+                // ask the user to enter a timecode
 				QString s = QInputDialog::getText(
 							this,
 							tr("Set Value"),
@@ -155,9 +212,16 @@ void LabelSlider::mouseReleaseEvent(QMouseEvent* ev) {
 							valueToString(internal_value)
 						);
 				if (s.isEmpty()) return;
-				d = timecode_to_frame(s, config.timecode_view, frame_rate); // string to frame number
+
+                // parse string timecode to a frame number
+                d = timecode_to_frame(s, config.timecode_view, frame_rate);
+
 			} else {
+
+                // ask the user to enter a normal number value
 				bool ok;
+
+                // percentages are stored 0.0 - 1.0 but displayed as 0% - 100%
 				d = QInputDialog::getDouble(
 							this,
 							tr("Set Value"),
@@ -171,6 +235,8 @@ void LabelSlider::mouseReleaseEvent(QMouseEvent* ev) {
 				if (!ok) return;
 				if (display_type == LABELSLIDER_PERCENT) d *= 0.01;
 			}
+
+            // if the value actually changed, trigger a change event
 			if (d != internal_value) {
 				set_previous_value();
 				set_value(d, true);