Fix widths of time columns for fonts with proportional figures

This still breaks when the 0 digit is narrower than some other
digit, but that's unlikely and the current behavior now matches
the original behavior when all times are < 10h.

Fixes #111 .

src/grid_column.cpp

@@ -159,9 +159,14 @@ struct GridColumnStartTime final : GridColumnTime {
 
 	int Width(const agi::Context *c, WidthHelper &helper) const override {
 		agi::Time max_time = max_value(&AssDialogue::Start, c->ass->Events);
-		if (!by_frame)
-			return helper(max_time.GetAssFormatted());
-		return helper(std::to_wstring(c->videoController->FrameAtTime(max_time, agi::vfr::START)));
+		std::string value = by_frame ? std::to_string(c->videoController->FrameAtTime(max_time, agi::vfr::START)) : max_time.GetAssFormatted();
+
+		for (char &c : value) {
+			if (c >= '0' && c <= '9')
+				c = '0';
+		}
+
+		return helper(value);
 	}
 };
 
@@ -177,9 +182,14 @@ struct GridColumnEndTime final : GridColumnTime {
 
 	int Width(const agi::Context *c, WidthHelper &helper) const override {
 		agi::Time max_time = max_value(&AssDialogue::End, c->ass->Events);
-		if (!by_frame)
-			return helper(max_time.GetAssFormatted());
-		return helper(std::to_wstring(c->videoController->FrameAtTime(max_time, agi::vfr::END)));
+		std::string value = by_frame ? std::to_string(c->videoController->FrameAtTime(max_time, agi::vfr::END)) : max_time.GetAssFormatted();
+
+		for (char &c : value) {
+			if (c >= '0' && c <= '9')
+				c = '0';
+		}
+
+		return helper(value);
 	}
 };