Merge pull request #1747 from Airblader/feature-1723

Implement "title_format"

docs/userguide

@@ -564,6 +564,8 @@ hide_edge_borders vertical
 
 === Arbitrary commands for specific windows (for_window)
 
+[[for_window]]
+
 With the +for_window+ command, you can let i3 execute any command when it
 encounters a specific window. This can be used to set windows to floating or to
 change their border style, for example.
@@ -2083,6 +2085,37 @@ Alternatively, if you do not want to mess with +i3-input+, you could create
 seperate bindings for a specific set of labels and then only use those labels.
 ///////////////////////////////////////////////////////////////////
 
+=== Window title format
+
+By default, i3 will simply print the X11 window title. Using +title_format+,
+this can be customized by setting the format to the desired output. This
+directive supports
+https://developer.gnome.org/pango/stable/PangoMarkupFormat.html[Pango markup]
+and the following placeholders which will be replaced:
+
++%title+::
+    The X11 window title (_NET_WM_NAME or WM_NAME as fallback).
+
+Using the <<for_window>> directive, you can set the title format for any window
+based on <<command_criteria>>.
+
+*Syntax*:
+---------------------
+title_format <format>
+---------------------
+
+*Examples*:
+-------------------------------------------------------------------------------------
+# give the focused window a prefix
+bindsym $mod+p title_format "Important | %title"
+
+# print all window titles bold
+for_window [class=".*"] title_format "<b>%title</b>"
+
+# print window titles of firefox windows red
+for_window [class="(?i)firefox"] title_format "<span foreground='red'>%title</span>"
+-------------------------------------------------------------------------------------
+
 === Changing border style
 
 To change the border of the current client, you can use +border normal+ to use the normal

include/commands.h

@@ -276,6 +276,12 @@ void cmd_move_scratchpad(I3_CMD);
  */
 void cmd_scratchpad_show(I3_CMD);
 
+/**
+ * Implementation of 'title_format <format>'
+ *
+ */
+void cmd_title_format(I3_CMD, char *format);
+
 /**
  * Implementation of 'rename workspace <name> to <name>'
  *

include/data.h

@@ -363,6 +363,8 @@ struct Window {
 
     /** The name of the window. */
     i3String *name;
+    /** The format with which the window's name should be displayed. */
+    char *title_format;
 
     /** The WM_WINDOW_ROLE of this window (for example, the pidgin buddy window
      * sets "buddy list"). Useful to match specific windows in assignments or

include/libi3.h

@@ -243,6 +243,11 @@ bool i3string_is_markup(i3String *str);
  */
 void i3string_set_markup(i3String *str, bool is_markup);
 
+/**
+ * Escape pango markup characters in the given string.
+ */
+i3String *i3string_escape_markup(i3String *str);
+
 /**
  * Returns the number of glyphs in an i3String.
  *
@@ -381,6 +386,12 @@ xcb_char2b_t *convert_utf8_to_ucs2(char *input, size_t *real_strlen);
  */
 void set_font_colors(xcb_gcontext_t gc, uint32_t foreground, uint32_t background);
 
+/**
+ * Returns true if and only if the current font is a pango font.
+ *
+ */
+bool font_is_pango(void);
+
 /**
  * Draws text onto the specified X drawable (normally a pixmap) at the
  * specified coordinates (from the top left corner of the leftmost, uppermost

libi3/font.c

@@ -340,6 +340,18 @@ void set_font_colors(xcb_gcontext_t gc, uint32_t foreground, uint32_t background
     }
 }
 
+/*
+ * Returns true if and only if the current font is a pango font.
+ *
+ */
+bool font_is_pango(void) {
+#if PANGO_SUPPORT
+    return savedFont->type == FONT_TYPE_PANGO;
+#else
+    return false;
+#endif
+}
+
 static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
 
 static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,

libi3/string.c

@@ -13,6 +13,10 @@
 #include <stdlib.h>
 #include <string.h>
 
+#if PANGO_SUPPORT
+#include <glib.h>
+#endif
+
 #include "libi3.h"
 
 struct _i3String {
@@ -185,6 +189,18 @@ void i3string_set_markup(i3String *str, bool is_markup) {
     str->is_markup = is_markup;
 }
 
+/*
+ * Escape pango markup characters in the given string.
+ */
+i3String *i3string_escape_markup(i3String *str) {
+#if PANGO_SUPPORT
+    const char *text = i3string_as_utf8(str);
+    return i3string_from_utf8(g_markup_escape_text(text, -1));
+#else
+    return str;
+#endif
+}
+
 /*
  * Returns the number of glyphs in an i3String.
  *

parser-specs/commands.spec

@@ -37,6 +37,7 @@ state INITIAL:
   'rename' -> RENAME
   'nop' -> NOP
   'scratchpad' -> SCRATCHPAD
+  'title_format' -> TITLE_FORMAT
   'mode' -> MODE
   'bar' -> BAR
 
@@ -374,6 +375,10 @@ state SCRATCHPAD:
   'show'
       -> call cmd_scratchpad_show()
 
+state TITLE_FORMAT:
+  format = string
+      -> call cmd_title_format($format)
+
 # bar (hidden_state hide|show|toggle)|(mode dock|hide|invisible|toggle) [<bar_id>]
 state BAR:
   bar_type = 'hidden_state'

src/commands.c

@@ -1899,6 +1899,35 @@ void cmd_scratchpad_show(I3_CMD) {
     ysuccess(true);
 }
 
+/*
+ * Implementation of 'title_format <format>'
+ *
+ */
+void cmd_title_format(I3_CMD, char *format) {
+    DLOG("setting title_format to \"%s\"\n", format);
+    HANDLE_EMPTY_MATCH;
+
+    owindow *current;
+    TAILQ_FOREACH(current, &owindows, owindows) {
+        if (current->con->window == NULL)
+            continue;
+
+        DLOG("setting title_format for %p / %s\n", current->con, current->con->name);
+        FREE(current->con->window->title_format);
+
+        /* If we only display the title without anything else, we can skip the parsing step,
+         * so we remove the title format altogether. */
+        if (strcasecmp(format, "%title") != 0)
+            current->con->window->title_format = sstrdup(format);
+
+        /* Make sure the window title is redrawn immediately. */
+        current->con->window->name_x_changed = true;
+    }
+
+    cmd_output->needs_tree_render = true;
+    ysuccess(true);
+}
+
 /*
  * Implementation of 'rename workspace [<name>] to <name>'
  *

src/x.c

@@ -302,6 +302,45 @@ void x_window_kill(xcb_window_t window, kill_window_t kill_window) {
     free(event);
 }
 
+static i3String *parse_title_format(char *format, i3String *_title) {
+    /* We need to ensure that we only escape the window title if pango
+     * is used by the current font. */
+    const bool is_markup = font_is_pango();
+
+    i3String *title = is_markup ? i3string_escape_markup(_title) : _title;
+    const char *escaped_title = i3string_as_utf8(title);
+
+    /* We have to first iterate over the string to see how much buffer space
+     * we need to allocate. */
+    int buffer_len = strlen(format) + 1;
+    for (char *walk = format; *walk != '\0'; walk++) {
+        if (STARTS_WITH(walk, "%title")) {
+            buffer_len = buffer_len - strlen("%title") + strlen(escaped_title);
+            walk += strlen("%title") - 1;
+        }
+    }
+
+    /* Now we can parse the format string. */
+    char buffer[buffer_len];
+    char *outwalk = buffer;
+    for (char *walk = format; *walk != '\0'; walk++) {
+        if (*walk != '%') {
+            *(outwalk++) = *walk;
+            continue;
+        }
+
+        if (STARTS_WITH(walk + 1, "title")) {
+            outwalk += sprintf(outwalk, "%s", escaped_title);
+            walk += strlen("title");
+        }
+    }
+    *outwalk = '\0';
+
+    i3String *formatted = i3string_from_utf8(buffer);
+    i3string_set_markup(formatted, is_markup);
+    return formatted;
+}
+
 /*
  * Draws the decoration of the given container onto its parent.
  *
@@ -549,10 +588,13 @@ void x_draw_decoration(Con *con) {
         I3STRING_FREE(mark);
     }
 
-    draw_text(win->name,
+    i3String *title = win->title_format == NULL ? win->name : parse_title_format(win->title_format, win->name);
+    draw_text(title,
               parent->pixmap, parent->pm_gc,
               con->deco_rect.x + logical_px(2) + indent_px, con->deco_rect.y + text_offset_y,
               con->deco_rect.width - logical_px(2) - indent_px - mark_width - logical_px(2));
+    if (win->title_format != NULL)
+        I3STRING_FREE(title);
 
 after_title:
     /* Since we don’t clip the text at all, it might in some cases be painted

testcases/t/187-commands-parser.t

@@ -144,7 +144,7 @@ is(parser_calls("\nworkspace test"),
 ################################################################################
 
 is(parser_calls('unknown_literal'),
-   "ERROR: Expected one of these tokens: <end>, '[', 'move', 'exec', 'exit', 'restart', 'reload', 'shmlog', 'debuglog', 'border', 'layout', 'append_layout', 'workspace', 'focus', 'kill', 'open', 'fullscreen', 'split', 'floating', 'mark', 'unmark', 'resize', 'rename', 'nop', 'scratchpad', 'mode', 'bar'\n" .
+   "ERROR: Expected one of these tokens: <end>, '[', 'move', 'exec', 'exit', 'restart', 'reload', 'shmlog', 'debuglog', 'border', 'layout', 'append_layout', 'workspace', 'focus', 'kill', 'open', 'fullscreen', 'split', 'floating', 'mark', 'unmark', 'resize', 'rename', 'nop', 'scratchpad', 'title_format', 'mode', 'bar'\n" .
    "ERROR: Your command: unknown_literal\n" .
    "ERROR:               ^^^^^^^^^^^^^^^",
    'error for unknown literal ok');