UI: tweak drawing of header status text for transparent headers.

source/blender/blenfont/BLF_api.h

@@ -102,6 +102,9 @@ void BLF_batch_draw_end(void);
 void BLF_draw_default(float x, float y, float z, const char *str, size_t len) ATTR_NONNULL();
 void BLF_draw_default_ascii(float x, float y, float z, const char *str, size_t len) ATTR_NONNULL();
 
+/* Set size and DPI, and return default font ID. */
+int BLF_set_default(void);
+
 /* Draw the string using the current font. */
 void BLF_draw_ex(int fontid, const char *str, size_t len, struct ResultBLF *r_info) ATTR_NONNULL(2);
 void BLF_draw(int fontid, const char *str, size_t len) ATTR_NONNULL(2);

source/blender/blenfont/intern/blf.c

@@ -570,6 +570,15 @@ void BLF_draw_default_ascii(float x, float y, float z, const char *str, size_t l
 	BLF_draw_ascii(global_font_default, str, len); /* XXX, use real length */
 }
 
+int BLF_set_default(void)
+{
+	ASSERT_DEFAULT_SET;
+
+	BLF_size(global_font_default, global_font_points, global_font_dpi);
+
+	return global_font_default;
+}
+
 static void blf_draw_gl__start(FontBLF *font)
 {
 	/*

source/blender/blenlib/BLI_string.h

@@ -85,6 +85,7 @@ size_t BLI_strnlen(const char *str, const size_t maxlen) ATTR_WARN_UNUSED_RESULT
 
 void BLI_str_tolower_ascii(char *str, const size_t len) ATTR_NONNULL();
 void BLI_str_toupper_ascii(char *str, const size_t len) ATTR_NONNULL();
+void BLI_str_rstrip(char *str) ATTR_NONNULL();
 int BLI_str_rstrip_float_zero(char *str, const char pad) ATTR_NONNULL();
 
 int BLI_str_index_in_array_n(const char *__restrict str, const char **__restrict str_array, const int str_array_len) ATTR_NONNULL();

source/blender/blenlib/intern/string.c

@@ -778,6 +778,21 @@ void BLI_str_toupper_ascii(char *str, const size_t len)
 			str[i] -= 'a' - 'A';
 }
 
+/**
+ * Strip whitespace from end of the string.
+ */
+void BLI_str_rstrip(char *str)
+{
+	for (int i = strlen(str) - 1; i > 0; i--) {
+		if (isspace(str[i])) {
+			str[i] = '\0';
+		}
+		else {
+			break;
+		}
+	}
+}
+
 /**
  * Strip trailing zeros from a float, eg:
  *   0.0000 -> 0.0

source/blender/editors/screen/area.c

@@ -393,6 +393,49 @@ static void region_draw_azones(ScrArea *sa, ARegion *ar)
 	GPU_blend(false);
 }
 
+static void region_draw_status_text(ScrArea *sa, ARegion *ar)
+{
+	bool overlap = ED_region_is_overlap(sa->spacetype, ar->regiontype);
+
+	if (overlap) {
+		GPU_clear_color(0.0, 0.0, 0.0, 0.0);
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
+	else {
+		UI_ThemeClearColor(TH_HEADER);
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
+
+	int fontid = BLF_set_default();
+
+	const float width = BLF_width(fontid, ar->headerstr, BLF_DRAW_STR_DUMMY_MAX);
+	const float x = UI_UNIT_X;
+	const float y = 0.4f * UI_UNIT_Y;
+
+	if (overlap) {
+		const float pad = 2.0f * UI_DPI_FAC;
+		const float x1 = x - (UI_UNIT_X - pad);
+		const float x2 = x + width + (UI_UNIT_X - pad);
+		const float y1 = pad;
+		const float y2 = ar->winy - pad;
+
+		GPU_blend_set_func_separate(GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA, GPU_ONE, GPU_ONE_MINUS_SRC_ALPHA);
+
+		float color[4] = {0.0f, 0.0f, 0.0f, 0.5f};
+		UI_GetThemeColor3fv(TH_BACK, color);
+		UI_draw_roundbox_corner_set(UI_CNR_ALL);
+		UI_draw_roundbox_aa(true, x1, y1, x2, y2, 4.0f, color);
+
+		UI_FontThemeColor(fontid, TH_TEXT);
+	}
+	else {
+		UI_FontThemeColor(fontid, TH_TEXT);
+	}
+
+	BLF_position(fontid, x, y, 0.0f);
+	BLF_draw(fontid, ar->headerstr, BLF_DRAW_STR_DUMMY_MAX);
+}
+
 /* Follow wmMsgNotifyFn spec */
 void ED_region_do_msg_notify_tag_redraw(
         bContext *UNUSED(C), wmMsgSubscribeKey *UNUSED(msg_key), wmMsgSubscribeValue *msg_val)
@@ -480,11 +523,7 @@ void ED_region_do_draw(bContext *C, ARegion *ar)
 	}
 	/* optional header info instead? */
 	else if (ar->headerstr) {
-		UI_ThemeClearColor(TH_HEADER);
-		glClear(GL_COLOR_BUFFER_BIT);
-
-		UI_FontThemeColor(BLF_default(), TH_TEXT);
-		BLF_draw_default(UI_UNIT_X, 0.4f * UI_UNIT_Y, 0.0f, ar->headerstr, BLF_DRAW_STR_DUMMY_MAX);
+		region_draw_status_text(sa, ar);
 	}
 	else if (at->draw) {
 		at->draw(C, ar);
@@ -671,6 +710,7 @@ void ED_area_status_text(ScrArea *sa, const char *str)
 				if (ar->headerstr == NULL)
 					ar->headerstr = MEM_mallocN(UI_MAX_DRAW_STR, "headerprint");
 				BLI_strncpy(ar->headerstr, str, UI_MAX_DRAW_STR);
+				BLI_str_rstrip(ar->headerstr);
 			}
 			else if (ar->headerstr) {
 				MEM_freeN(ar->headerstr);