feat: add animated focus transitions for window titles and taskbar colors

include/client.h

@@ -70,4 +70,8 @@ Client *client_get_prev(Client *client);
 Client *client_get_first(void);
 Client *client_get_last(void);
 
+void client_start_focus_animation(Client *client, bool gaining_focus);
+unsigned long client_get_animated_title_color(Client *client);
+void client_update_animations(void);
+
 #endif

include/dwn.h

@@ -87,6 +87,14 @@ typedef struct {
     long timestamp;
 } SnapConstraint;
 
+typedef struct {
+    long start_time;
+    float progress;
+    unsigned long from_color;
+    unsigned long to_color;
+    bool active;
+} ColorAnimation;
+
 typedef struct Client Client;
 typedef struct Workspace Workspace;
 typedef struct Monitor Monitor;
@@ -106,6 +114,8 @@ struct Client {
     char title[256];
     char class[64];
     SnapConstraint snap;
+    unsigned long taskbar_color;
+    ColorAnimation title_anim;
     Client *next;
     Client *prev;
     Client *mru_next;
@@ -166,6 +176,7 @@ typedef struct {
     GC gc;
     XFontStruct *font;
     XftFont *xft_font;
+    XftFont *xft_font_bold;
     Colormap colormap;
 
     Client *drag_client;

include/util.h

@@ -53,6 +53,11 @@ char *expand_path(const char *path);
 
 unsigned long parse_color(const char *color_str);
 void color_to_rgb(unsigned long color, int *r, int *g, int *b);
+unsigned long rgb_to_pixel(int r, int g, int b);
+unsigned long generate_unique_color(void);
+unsigned long adjust_color_for_background(unsigned long color, unsigned long bg);
+unsigned long interpolate_color(unsigned long from, unsigned long to, float progress);
+unsigned long dim_color(unsigned long color, float factor);
 
 long get_time_ms(void);
 void sleep_ms(int ms);