Implement showing window icons in titlebar (#4439)

This feature defaults to off, and can be turned on for individual windows,
or (with for_window) for all new windows. See the userguide change.

This commit is partially based on work by:

• Marius Muja
• mickael9
• Esteve Varela Colominas
• Bernardo Menicagli

RELEASE-NOTES-next

@@ -36,6 +36,7 @@ option is enabled and only then sets a screenshot as background.
   • i3-dump-log -f now uses UNIX sockets instead of pthreads. The UNIX socket approach
     should be more reliable and also more portable.
   • Implement the include config directive
+  • Implement optionally showing window icons in titlebar
   • Allow for_window to match against WM_CLIENT_MACHINE
   • Add %machine placeholder (WM_CLIENT_MACHINE) to title_format
   • Allow multiple output names in 'move container|workspace to output'

docs/userguide

@@ -2703,6 +2703,32 @@ for_window [class=".*"] title_format "<b>%title</b>"
 for_window [class="(?i)firefox"] title_format "<span foreground='red'>%title</span>"
 -------------------------------------------------------------------------------------
 
+[[title_window_icon]]
+=== Window title icon
+
+By default, i3 does not display the window icon in the title bar.
+
+Starting with i3 v4.20, you can optionally enable window icons either for
+specific windows or for all windows (using the <<for_window>> directive).
+
+*Syntax*:
+-----------------------------
+title_window_icon <yes|no>
+title_window_icon padding <px>
+------------------------------
+
+*Examples*:
+-------------------------------------------------------------------------------------
+# show the window icon for the focused window to make it stand out
+bindsym $mod+p title_window_icon on
+
+# enable window icons for all windows
+for_window [class=".*"] title_window_icon on
+
+# enable window icons for all windows with extra horizontal padding
+for_window [class=".*"] title_window_icon padding 3px
+-------------------------------------------------------------------------------------
+
 === Changing border style
 
 To change the border of the current client, you can use +border normal+ to use the normal

include/commands.h

@@ -331,3 +331,9 @@ void cmd_shmlog(I3_CMD, const char *argument);
  *
  */
 void cmd_debuglog(I3_CMD, const char *argument);
+
+/**
+ * Implementation of 'title_window_icon <yes|no>' and 'title_window_icon padding <px>'
+ *
+ */
+void cmd_title_window_icon(I3_CMD, const char *enable, int padding);

include/data.h

@@ -15,6 +15,7 @@
 #include <xcb/randr.h>
 #include <pcre.h>
 #include <sys/time.h>
+#include <cairo/cairo.h>
 
 #include "queue.h"
 
@@ -471,6 +472,9 @@ struct Window {
     double min_aspect_ratio;
     double max_aspect_ratio;
 
+    /** Window icon, as Cairo surface */
+    cairo_surface_t *icon;
+
     /** The window has a nonrectangular shape. */
     bool shaped;
     /** The window has a nonrectangular input shape. */
@@ -656,6 +660,11 @@ struct Con {
     /** The format with which the window's name should be displayed. */
     char *title_format;
 
+    /** Whether the window icon should be displayed, and with what padding. -1
+      * means display no window icon (default behavior), 0 means display without
+      * any padding, 1 means display with 1 pixel of padding and so on. */
+    int window_icon_padding;
+
     /* a sticky-group is an identifier which bundles several containers to a
      * group. The contents are shared between all of them, that is they are
      * displayed on whichever of the containers is currently visible */

include/i3-atoms_rest.xmacro.h

@@ -3,6 +3,7 @@
 xmacro(_NET_WM_USER_TIME) \
 xmacro(_NET_STARTUP_ID) \
 xmacro(_NET_WORKAREA) \
+xmacro(_NET_WM_ICON) \
 xmacro(WM_PROTOCOLS) \
 xmacro(WM_DELETE_WINDOW) \
 xmacro(UTF8_STRING) \

include/libi3.h

@@ -611,6 +611,11 @@ color_t draw_util_hex_to_color(const char *color);
  */
 void draw_util_text(i3String *text, surface_t *surface, color_t fg_color, color_t bg_color, int x, int y, int max_width);
 
+/**
+ * Draw the given image using libi3.
+ */
+void draw_util_image(cairo_surface_t *image, surface_t *surface, int x, int y, int width, int height);
+
 /**
  * Draws a filled rectangle.
  * This function is a convenience wrapper and takes care of flushing the
@@ -668,3 +673,9 @@ void set_screenshot_as_wallpaper(xcb_connection_t *conn, xcb_screen_t *screen);
  * content of the window.
  */
 bool is_background_set(xcb_connection_t *conn, xcb_screen_t *screen);
+
+/**
+ * Reports whether str represents the enabled state (1, yes, true, …).
+ *
+ */
+bool boolstr(const char *str);

include/window.h

@@ -101,3 +101,9 @@ void window_update_motif_hints(i3Window *win, xcb_get_property_reply_t *prop, bo
  *
  */
 void window_update_machine(i3Window *win, xcb_get_property_reply_t *prop);
+
+/**
+ * Updates the _NET_WM_ICON
+ *
+ */
+void window_update_icon(i3Window *win, xcb_get_property_reply_t *prop);

libi3/boolstr.c

@@ -0,0 +1,25 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
+ *
+ */
+#include "libi3.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/*
+ * Reports whether str represents the enabled state (1, yes, true, …).
+ *
+ */
+bool boolstr(const char *str) {
+    return (strcasecmp(str, "1") == 0 ||
+            strcasecmp(str, "yes") == 0 ||
+            strcasecmp(str, "true") == 0 ||
+            strcasecmp(str, "on") == 0 ||
+            strcasecmp(str, "enable") == 0 ||
+            strcasecmp(str, "active") == 0);
+}

libi3/draw_util.c

@@ -141,6 +141,30 @@ void draw_util_text(i3String *text, surface_t *surface, color_t fg_color, color_
     cairo_surface_mark_dirty(surface->surface);
 }
 
+/**
+ * Draw the given image using libi3.
+ * This function is a convenience wrapper and takes care of flushing the
+ * surface as well as restoring the cairo state.
+ *
+ */
+void draw_util_image(cairo_surface_t *image, surface_t *surface, int x, int y, int width, int height) {
+    RETURN_UNLESS_SURFACE_INITIALIZED(surface);
+
+    cairo_save(surface->cr);
+
+    cairo_translate(surface->cr, x, y);
+
+    const int src_width = cairo_image_surface_get_width(image);
+    const int src_height = cairo_image_surface_get_height(image);
+    double scale = MIN((double)width / src_width, (double)height / src_height);
+    cairo_scale(surface->cr, scale, scale);
+
+    cairo_set_source_surface(surface->cr, image, 0, 0);
+    cairo_paint(surface->cr);
+
+    cairo_restore(surface->cr);
+}
+
 /*
  * Draws a filled rectangle.
  * This function is a convenience wrapper and takes care of flushing the

meson.build

@@ -325,6 +325,7 @@ ev_dep = cc.find_library('ev')
 inc = include_directories('include')
 
 libi3srcs = [
+  'libi3/boolstr.c',
   'libi3/create_socket.c',
   'libi3/dpi.c',
   'libi3/draw_util.c',

parser-specs/commands.spec

@@ -40,6 +40,7 @@ state INITIAL:
   'scratchpad' -> SCRATCHPAD
   'swap' -> SWAP
   'title_format' -> TITLE_FORMAT
+  'title_window_icon' -> TITLE_WINDOW_ICON
   'mode' -> MODE
   'bar' -> BAR
 
@@ -462,6 +463,20 @@ state TITLE_FORMAT:
   format = string
       -> call cmd_title_format($format)
 
+state TITLE_WINDOW_ICON:
+  'padding'
+    -> TITLE_WINDOW_ICON_PADDING
+  enable = '1', 'yes', 'true', 'on', 'enable', 'active', '0', 'no', 'false', 'off', 'disable', 'inactive'
+    -> call cmd_title_window_icon($enable, 0)
+
+state TITLE_WINDOW_ICON_PADDING:
+  end
+    -> call cmd_title_window_icon($enable, &padding)
+  'px'
+    -> call cmd_title_window_icon($enable, &padding)
+  padding = number
+    ->
+
 # bar (hidden_state hide|show|toggle)|(mode dock|hide|invisible|toggle) [<bar_id>]
 state BAR:
   'hidden_state'

src/commands.c

@@ -2037,6 +2037,35 @@ void cmd_title_format(I3_CMD, const char *format) {
     ysuccess(true);
 }
 
+/*
+ * Implementation of 'title_window_icon <yes|no>' and 'title_window_icon padding <px>'
+ *
+ */
+void cmd_title_window_icon(I3_CMD, const char *enable, int padding) {
+    if (enable != NULL && !boolstr(enable)) {
+        padding = -1;
+    }
+    DLOG("setting window_icon=%d\n", padding);
+    HANDLE_EMPTY_MATCH;
+
+    owindow *current;
+    TAILQ_FOREACH (current, &owindows, owindows) {
+        DLOG("setting window_icon for %p / %s\n", current->con, current->con->name);
+        current->con->window_icon_padding = padding;
+
+        if (current->con->window != NULL) {
+            /* Make sure the window title is redrawn immediately. */
+            current->con->window->name_x_changed = true;
+        } else {
+            /* For windowless containers we also need to force the redrawing. */
+            FREE(current->con->deco_render_params);
+        }
+    }
+
+    cmd_output->needs_tree_render = true;
+    ysuccess(true);
+}
+
 /*
  * Implementation of 'rename workspace [<name>] to <name>'
  *

src/con.c

@@ -43,6 +43,7 @@ Con *con_new_skeleton(Con *parent, i3Window *window) {
     new->window = window;
     new->border_style = config.default_border;
     new->current_border_width = -1;
+    new->window_icon_padding = -1;
     if (window) {
         new->depth = window->depth;
     } else {

src/config_directives.c

@@ -124,15 +124,6 @@ CFGFUN(criteria_add, const char *ctype, const char *cvalue) {
  * Utility functions
  ******************************************************************************/
 
-static bool eval_boolstr(const char *str) {
-    return (strcasecmp(str, "1") == 0 ||
-            strcasecmp(str, "yes") == 0 ||
-            strcasecmp(str, "true") == 0 ||
-            strcasecmp(str, "on") == 0 ||
-            strcasecmp(str, "enable") == 0 ||
-            strcasecmp(str, "active") == 0);
-}
-
 /*
  * A utility function to convert a string containing the group and modifiers to
  * the corresponding bit mask.
@@ -316,14 +307,14 @@ CFGFUN(hide_edge_borders, const char *borders) {
         config.hide_edge_borders = HEBM_BOTH;
     else if (strcmp(borders, "none") == 0)
         config.hide_edge_borders = HEBM_NONE;
-    else if (eval_boolstr(borders))
+    else if (boolstr(borders))
         config.hide_edge_borders = HEBM_VERTICAL;
     else
         config.hide_edge_borders = HEBM_NONE;
 }
 
 CFGFUN(focus_follows_mouse, const char *value) {
-    config.disable_focus_follows_mouse = !eval_boolstr(value);
+    config.disable_focus_follows_mouse = !boolstr(value);
 }
 
 CFGFUN(mouse_warping, const char *value) {
@@ -334,19 +325,19 @@ CFGFUN(mouse_warping, const char *value) {
 }
 
 CFGFUN(force_xinerama, const char *value) {
-    config.force_xinerama = eval_boolstr(value);
+    config.force_xinerama = boolstr(value);
 }
 
 CFGFUN(disable_randr15, const char *value) {
-    config.disable_randr15 = eval_boolstr(value);
+    config.disable_randr15 = boolstr(value);
 }
 
 CFGFUN(focus_wrapping, const char *value) {
     if (strcmp(value, "force") == 0) {
         config.focus_wrapping = FOCUS_WRAPPING_FORCE;
     } else if (strcmp(value, "workspace") == 0) {
         config.focus_wrapping = FOCUS_WRAPPING_WORKSPACE;
-    } else if (eval_boolstr(value)) {
+    } else if (boolstr(value)) {
         config.focus_wrapping = FOCUS_WRAPPING_ON;
     } else {
         config.focus_wrapping = FOCUS_WRAPPING_OFF;
@@ -355,7 +346,7 @@ CFGFUN(focus_wrapping, const char *value) {
 
 CFGFUN(force_focus_wrapping, const char *value) {
     /* Legacy syntax. */
-    if (eval_boolstr(value)) {
+    if (boolstr(value)) {
         config.focus_wrapping = FOCUS_WRAPPING_FORCE;
     } else {
         /* For "force_focus_wrapping off", don't enable or disable
@@ -367,7 +358,7 @@ CFGFUN(force_focus_wrapping, const char *value) {
 }
 
 CFGFUN(workspace_back_and_forth, const char *value) {
-    config.workspace_auto_back_and_forth = eval_boolstr(value);
+    config.workspace_auto_back_and_forth = boolstr(value);
 }
 
 CFGFUN(fake_outputs, const char *outputs) {
@@ -409,7 +400,7 @@ CFGFUN(title_align, const char *alignment) {
 }
 
 CFGFUN(show_marks, const char *value) {
-    config.show_marks = eval_boolstr(value);
+    config.show_marks = boolstr(value);
 }
 
 static char *current_workspace = NULL;
@@ -597,7 +588,7 @@ CFGFUN(bar_output, const char *output) {
 }
 
 CFGFUN(bar_verbose, const char *verbose) {
-    current_bar->verbose = eval_boolstr(verbose);
+    current_bar->verbose = boolstr(verbose);
 }
 
 CFGFUN(bar_modifier, const char *modifiers) {
@@ -717,23 +708,23 @@ CFGFUN(bar_status_command, const char *command) {
 }
 
 CFGFUN(bar_binding_mode_indicator, const char *value) {
-    current_bar->hide_binding_mode_indicator = !eval_boolstr(value);
+    current_bar->hide_binding_mode_indicator = !boolstr(value);
 }
 
 CFGFUN(bar_workspace_buttons, const char *value) {
-    current_bar->hide_workspace_buttons = !eval_boolstr(value);
+    current_bar->hide_workspace_buttons = !boolstr(value);
 }
 
 CFGFUN(bar_workspace_min_width, const long width) {
     current_bar->workspace_min_width = width;
 }
 
 CFGFUN(bar_strip_workspace_numbers, const char *value) {
-    current_bar->strip_workspace_numbers = eval_boolstr(value);
+    current_bar->strip_workspace_numbers = boolstr(value);
 }
 
 CFGFUN(bar_strip_workspace_name, const char *value) {
-    current_bar->strip_workspace_name = eval_boolstr(value);
+    current_bar->strip_workspace_name = boolstr(value);
 }
 
 CFGFUN(bar_start) {