popup: follow GDK_SCALE on HiDPI

The popup was 32-pixel rows whatever the display; next to 2x application
text it was small. Its metrics now scale with the daemon's GDK_SCALE,
the setting the applications use.

README.md

@@ -45,8 +45,9 @@ sends `XNSpotLocation` gets the popup at that spot whatever its preedit
 style; otherwise the popup sits under the focus window, or under the client
 window when no focus window is set.
 
-The popup is an X11 window, XIM is X11-only, and GTK popup placement converts
-the GTK caret to X11 root coordinates. There is no native Wayland popup
+The popup is an X11 window sized by `GDK_SCALE` on HiDPI displays, XIM is
+X11-only, and GTK popup placement converts the GTK caret to X11 root
+coordinates. There is no native Wayland popup
 surface or Wayland caret positioning. GTK and IBus clients can still use
 inline preedit where their display environment supports it.
 

dat.h

@@ -18,12 +18,6 @@ enum
 	LangEMOJI	= 0x05,
 	LangVI	= 0x16,
 
-	Fontsz	= 32,
-	PopupPad	= 4,
-	PopupSep	= 1,
-	PopupNumw	= Fontsz,
-	PopupTextw	= 12*Fontsz,
-	PopupBasew	= 2*PopupPad + PopupNumw + PopupTextw,
 	Maxrunes	= 64,
 	Maxutf	= Maxrunes * UTFmax + 1,
 };
@@ -33,7 +27,6 @@ enum
 	Maxclients	= 64,
 	Maxkouho	= 128,
 	Maxdisp		= 9,
-	Imgh		= 2*PopupPad + (Maxdisp + 2)*Fontsz + PopupSep,
 
 	Colfg	= 0x000000,
 	Colbg	= 0xffffff,
@@ -42,6 +35,16 @@ enum
 	Colselfg	= 0xffffff,
 };
 
+/* Popup metrics in pixels; popupscale is GDK_SCALE, for HiDPI. */
+extern int popupscale;
+#define Fontsz		(32*popupscale)
+#define PopupPad	(4*popupscale)
+#define PopupSep	popupscale
+#define PopupNumw	Fontsz
+#define PopupTextw	(12*Fontsz)
+#define PopupBasew	(2*PopupPad + PopupNumw + PopupTextw)
+#define Imgh		(2*PopupPad + (Maxdisp + 2)*Fontsz + PopupSep)
+
 typedef struct Str Str;
 struct Str
 {

popup_layout.c

@@ -5,6 +5,8 @@ enum {
 	Asciitofull = 0xFEE0,
 };
 
+int popupscale = 1;
+
 static void
 fill(u32int *buf, int n, u32int color)
 {

tests/font_test.c

@@ -5,12 +5,13 @@
 enum
 {
 	Guard = 8,
-	Testw = 6 * Fontsz,
-	Testh = 3 * Fontsz,
-	Testn = Testw * Testh,
 	Rgbmask = 0xffffff,
 };
 
+#define Testw	(6 * Fontsz)
+#define Testh	(3 * Fontsz)
+#define Testn	(Testw * Testh)
+
 static u32int guardcolor = 0x5a5a5a5a;
 
 static void

tests/popup_test.c

@@ -40,7 +40,7 @@ checkpadding(struct ct *t, u32int *img, Popup *p)
 void
 popup_layout(struct ct *t)
 {
-	static int tinyheight[] = {
+	int tinyheight[] = {
 		1, PopupPad, 2*PopupPad + Fontsz - 1,
 	};
 	static const struct {

win.c

@@ -206,7 +206,11 @@ wininit(void)
 	xcb_randr_query_version_cookie_t rc;
 	xcb_randr_query_version_reply_t *rr;
 	const xcb_query_extension_reply_t *rext;
+	char *scale;
 
+	scale = getenv("GDK_SCALE");
+	if(scale != nil && atoi(scale) > 1)
+		popupscale = min(atoi(scale), 4);
 	conn = xcb_connect(nil, &n);
 	if(xcb_connection_has_error(conn)){
 		fprint(2, "strans: popup disabled: cannot connect to X display\n");