improve tooltip placement on sidebar (#8908)

src/floating_label.cpp

@@ -104,6 +104,11 @@ rect floating_label::get_bg_rect(const rect& text_rect) const
 	};
 }
 
+void floating_label::clear_texture()
+{
+	tex_.reset();
+}
+
 bool floating_label::create_texture()
 {
 	if(video::headless()) {

src/floating_label.hpp

@@ -86,6 +86,8 @@ public:
 	 */
 	bool create_texture();
 
+	void clear_texture();
+
 	/** Return the size of the label in drawing coordinates */
 	SDL_Point get_draw_size() const
 	{

src/tooltips.cpp

@@ -33,6 +33,7 @@ namespace {
 
 static const int font_size = font::SIZE_SMALL;
 static const int text_width = 400;
+static const double height_fudge = 0.95;  // An artificial "border" to keep tip text from crowding lower edge of viewing area
 
 struct tooltip
 {
@@ -60,16 +61,56 @@ void tooltip::init_label()
 	rect game_canvas = video::game_canvas();
 	unsigned int border = 10;
 
+	rect huge;
+	huge.h=1000000;
+	huge.w=1000000;
+
 	label.set_font_size(font_size);
 	label.set_color(font::NORMAL_COLOR);
-	label.set_clip_rect(game_canvas);
-	label.set_width(text_width);
+	label.set_clip_rect(huge);
+	label.set_width(text_width);   // If tooltip will be too tall for game_canvas, this could be scaled up appropriately
 	label.set_alignment(font::LEFT_ALIGN);
 	label.set_bg_color(bgcolor);
 	label.set_border_size(border);
 
 	label.create_texture();
 
+	point lsize = label.get_draw_size();
+	int new_text_width = text_width * static_cast<float>(lsize.y)/game_canvas.h;  // If necessary, scale width to reduce height while preserving area of label
+	while((lsize.y > game_canvas.h*height_fudge) && (lsize.x < game_canvas.w)) {
+		// Scaling the tip to reduce height is hard, since making a texture wider is no guarantee that there will be fewer lines of text:
+		//
+		// This block of text is just
+		// as tall as the other one.
+		//
+		// This block of text is just as tall as the other
+		// one.
+		//
+		// Creating this over and over may not be the most efficient route, but it will work and will be quite rare (tip taller than screen).
+		bool wont_fit = false;
+		if(new_text_width>game_canvas.w) {
+			new_text_width=game_canvas.w;
+			wont_fit = true;
+		}
+		DBG_FT << "lsize.x,y = " << lsize.x << "," << lsize.y << ", new_text_width = " << new_text_width;
+
+		label.set_width(new_text_width);
+		label.clear_texture();
+		label.create_texture();
+
+		lsize = label.get_draw_size();
+		DBG_FT << "new label lsize.x,y = " << lsize.x << "," << lsize.y;
+		if(wont_fit) {
+			break;
+		}
+		new_text_width *= 1.3;
+	}
+	// I don't know if it's strictly necessary to create the texture yet again just to make sure the clip_rect is set to game_canvas
+	// but it seems like the safe course of action.
+	label.set_clip_rect(game_canvas);
+	label.clear_texture();
+	label.create_texture();
+
 	update_label_pos();
 }
 
@@ -80,21 +121,42 @@ void tooltip::update_label_pos()
 	point lsize = label.get_draw_size();
 	loc = {0, 0, lsize.x, lsize.y};
 
-	// See if there is enough room to fit it above the tip area
+	DBG_FT << "\nupdate_label_pos() Start: loc = " << loc.x << "," << loc.y << " origin = " << origin.x << "," << origin.y;
+
 	if(origin.y > loc.h) {
+		// There is enough room to fit it above the tip area
 		loc.y = origin.y - loc.h;
-	} else {
+		DBG_FT << "\tAbove: loc = " << loc.x << "," << loc.y << " origin = " << origin.x << "," << origin.y;
+	} else if((origin.y + origin.h + loc.h) <= game_canvas.h*height_fudge) {
+		// There is enough room to fit it below the tip area
 		loc.y = origin.y + origin.h;
+		DBG_FT << "\tBelow: loc = " << loc.x << "," << loc.y << " origin = " << origin.x << "," << origin.y;
+	} else if(((origin.y + origin.h/2 - loc.h/2) >= 0) &&
+		  ((origin.y + origin.h/2 + loc.h/2) <= game_canvas.h*height_fudge)) {
+		// There is enough room to center it at the tip area
+		loc.y = origin.y + origin.h/2 - loc.h/2;
+		DBG_FT << "\tCenter: loc = " << loc.x << "," << loc.y << " origin = " << origin.x << "," << origin.y;
+	} else if(loc.h <= game_canvas.h*0.95) {
+		// There is enough room to center it
+		loc.y = game_canvas.h/2 - loc.h/2;
+		DBG_FT << "\tScreen Center: loc = " << loc.x << "," << loc.y << " origin = " << origin.x << "," << origin.y;
+	} else {
+		// It doesn't fit
+		loc.y = 0;
+		DBG_FT << "\tToo big: loc = " << loc.x << "," << loc.y << " origin = " << origin.x << "," << origin.y;
 	}
 
+	DBG_FT << "\tBefore x adjust: loc.x,y,w,h = " << loc.x << "," << loc.y << "," << loc.w << "," << loc.h << "  origin = " << origin.x << "," << origin.y;
 	// Try to keep it within the screen
 	loc.x = origin.x;
-	if(loc.x < 0) {
-		loc.x = 0;
-	} else if(loc.x + loc.w > game_canvas.w) {
+	if(loc.x + loc.w > game_canvas.w) {
 		loc.x = game_canvas.w - loc.w;
 	}
+	if(loc.x < 0) {
+		loc.x = 0;
+	}
 
+	DBG_FT << "\tFinal: loc.x,y,w,h = " << loc.x << "," << loc.y << "," << loc.w << "," << loc.h << "  origin = " << origin.x << "," << origin.y;
 	label.set_position(loc.x, loc.y);
 }