core: add key alt+backspace, change behavior of key ctrl+w (closes #559)

The key ctrl+w now deletes one word until whitespace.

The new key alt+backspace deletes one word (same behavior as ctrl+w in previous
releases).

src/core/wee-command.c

@@ -3294,6 +3294,8 @@ COMMAND_CALLBACK(input)
         gui_input_delete_next_char (buffer);
     else if (string_strcasecmp (argv[1], "delete_previous_word") == 0)
         gui_input_delete_previous_word (buffer);
+    else if (string_strcasecmp (argv[1], "delete_previous_word_whitespace") == 0)
+        gui_input_delete_previous_word_whitespace (buffer);
     else if (string_strcasecmp (argv[1], "delete_next_word") == 0)
         gui_input_delete_next_word (buffer);
     else if (string_strcasecmp (argv[1], "delete_beginning_of_line") == 0)
@@ -7985,6 +7987,8 @@ command_init ()
            "  delete_previous_char: delete previous char\n"
            "  delete_next_char: delete next char\n"
            "  delete_previous_word: delete previous word\n"
+           "  delete_previous_word_whitespace: delete previous word "
+           "(until whitespace)\n"
            "  delete_next_word: delete next word\n"
            "  delete_beginning_of_line: delete from beginning of line until "
            "cursor\n"
@@ -8041,7 +8045,8 @@ command_init ()
         "search_text || search_switch_case || search_switch_regex || "
         "search_switch_where || search_previous || search_next || "
         "search_stop_here || search_stop || delete_previous_char || "
-        "delete_next_char || delete_previous_word || delete_next_word || "
+        "delete_next_char || delete_previous_word || "
+        "delete_previous_word_whitespace || delete_next_word || "
         "delete_beginning_of_line || delete_end_of_line || delete_line || "
         "clipboard_paste || transpose_chars || undo || redo || "
         "move_beginning_of_line || move_end_of_line || move_previous_char || "

src/core/wee-string.c

@@ -1109,6 +1109,20 @@ string_convert_escaped_chars (const char *string)
     return output;
 }
 
+/*
+ * Checks if first char of string is a whitespace (space or tab).
+ *
+ * Returns:
+ *   1: first char is whitespace
+ *   0: first char is not whitespace
+ */
+
+int
+string_is_whitespace_char (const char *string)
+{
+    return (string && ((string[0] == ' ') || string[0] == '\t')) ? 1 : 0;
+}
+
 /*
  * Checks if first char of string is a "word char".
  *

src/core/wee-string.h

@@ -71,6 +71,7 @@ extern char *string_remove_quotes (const char *string, const char *quotes);
 extern char *string_strip (const char *string, int left, int right,
                            const char *chars);
 extern char *string_convert_escaped_chars (const char *string);
+extern int string_is_whitespace_char (const char *string);
 extern int string_is_word_char_highlight (const char *string);
 extern int string_is_word_char_input (const char *string);
 extern char *string_mask_to_regex (const char *mask);

src/gui/curses/gui-curses-key.c

@@ -93,7 +93,8 @@ gui_key_default_bindings (int context)
         BIND(/* m-_           */ "meta-_",             "/input redo");
         BIND(/* <del>         */ "meta2-3~",           "/input delete_next_char");
         BIND(/* ^D            */ "ctrl-D",             "/input delete_next_char");
-        BIND(/* ^W            */ "ctrl-W",             "/input delete_previous_word");
+        BIND(/* ^W            */ "ctrl-W",             "/input delete_previous_word_whitespace");
+        BIND(/* m-<backspace> */ "meta-ctrl-?",        "/input delete_previous_word");
         BIND(/* ^X            */ "ctrl-X",             "/input switch_active_buffer");
         BIND(/* m-x           */ "meta-x",             "/input zoom_merged_buffer");
         BIND(/* m-d           */ "meta-d",             "/input delete_next_word");

src/gui/gui-input.c

@@ -95,7 +95,7 @@ gui_input_replace_input (struct t_gui_buffer *buffer, const char *new_input)
     int size, length;
     char *input_utf8;
 
-    input_utf8 = strdup (new_input);
+    input_utf8 = strdup ((new_input) ? new_input : "");
     if (input_utf8)
     {
         utf8_normalize (input_utf8, '?');
@@ -838,13 +838,44 @@ gui_input_delete_next_char (struct t_gui_buffer *buffer)
 }
 
 /*
- * Deletes previous word (default key: ctrl-W).
+ * Delete the range between two positions and copy the content to the
+ * clipboard.
+ */
+
+void
+gui_input_delete_range (struct t_gui_buffer *buffer,
+                        char *start,
+                        char *end)
+{
+    int size_deleted, length_deleted;
+
+    size_deleted = utf8_next_char (end) - start;
+    length_deleted = utf8_strnlen (start, size_deleted);
+
+    gui_input_clipboard_copy (start, size_deleted);
+
+    memmove (start, start + size_deleted, strlen (start + size_deleted));
+
+    if (gui_input_optimize_size (
+            buffer,
+            buffer->input_buffer_size - size_deleted,
+            buffer->input_buffer_length - length_deleted))
+    {
+        buffer->input_buffer[buffer->input_buffer_size] = '\0';
+        buffer->input_buffer_pos -= length_deleted;
+    }
+    gui_input_text_changed_modifier_and_signal (buffer,
+                                                1, /* save undo */
+                                                1); /* stop completion */
+}
+
+/*
+ * Deletes previous word (default key: alt-backspace).
  */
 
 void
 gui_input_delete_previous_word (struct t_gui_buffer *buffer)
 {
-    int length_deleted, size_deleted;
     char *start, *string;
 
     if (buffer->input && (buffer->input_buffer_pos > 0))
@@ -872,24 +903,45 @@ gui_input_delete_previous_word (struct t_gui_buffer *buffer)
         else
             string = buffer->input_buffer;
 
-        size_deleted = utf8_next_char (start) - string;
-        length_deleted = utf8_strnlen (string, size_deleted);
+        gui_input_delete_range (buffer, string, start);
+    }
+}
 
-        gui_input_clipboard_copy (string, size_deleted);
+/*
+ * Deletes previous word until whitespace (default key: ctrl-W).
+ */
 
-        memmove (string, string + size_deleted, strlen (string + size_deleted));
+void
+gui_input_delete_previous_word_whitespace (struct t_gui_buffer *buffer)
+{
+    char *start, *string;
 
-        if (gui_input_optimize_size (
-                buffer,
-                buffer->input_buffer_size - size_deleted,
-                buffer->input_buffer_length - length_deleted))
+    if (buffer->input && (buffer->input_buffer_pos > 0))
+    {
+        gui_buffer_undo_snap (buffer);
+        start = (char *)utf8_add_offset (buffer->input_buffer,
+                                         buffer->input_buffer_pos - 1);
+        string = start;
+        /* move to the left, skipping whitespace */
+        while (string && string_is_whitespace_char (string))
         {
-            buffer->input_buffer[buffer->input_buffer_size] = '\0';
-            buffer->input_buffer_pos -= length_deleted;
+            string = (char *)utf8_prev_char (buffer->input_buffer, string);
         }
-        gui_input_text_changed_modifier_and_signal (buffer,
-                                                    1, /* save undo */
-                                                    1); /* stop completion */
+        /* move to the left until we reach a char which is not whitespace */
+        if (string)
+        {
+            while (string && !string_is_whitespace_char (string))
+            {
+                string = (char *)utf8_prev_char (buffer->input_buffer, string);
+            }
+        }
+
+        if (string)
+            string = (char *)utf8_next_char (string);
+        else
+            string = buffer->input_buffer;
+
+        gui_input_delete_range (buffer, string, start);
     }
 }
 

src/gui/gui-input.h

@@ -56,6 +56,7 @@ extern void gui_input_search_stop (struct t_gui_buffer *buffer);
 extern void gui_input_delete_previous_char (struct t_gui_buffer *buffer);
 extern void gui_input_delete_next_char (struct t_gui_buffer *buffer);
 extern void gui_input_delete_previous_word (struct t_gui_buffer *buffer);
+extern void gui_input_delete_previous_word_whitespace (struct t_gui_buffer *buffer);
 extern void gui_input_delete_next_word (struct t_gui_buffer *buffer);
 extern void gui_input_delete_beginning_of_line (struct t_gui_buffer *buffer);
 extern void gui_input_delete_end_of_line (struct t_gui_buffer *buffer);