textarea: implement NS_KEY_DELETE_WORD_{LEFT,RIGHT}

NS_KEY_DELETE_WORD_{LEFT,RIGHT} have been added to
include/netsurf/keypress.h and implemented in desktop/textarea.c

An unsigned int, caret_copy, has been added since both of these require
a temporary variable to hold the original position of the caret.

The LEFT one deletes separators towards the left till it encounters a
non-separator and then deletes the non-separators until it encounters a
separator. The caret is moved towards the left by the number of
characters deleted.

The RIGHT one does the same towards the right, but the caret is kept at
its original position.

These are intended to be mapped to Ctrl+Backspace and Ctrl+Delete by
most frontends.

Additionally, some style and typo fixes have been made.

1 files changed, 93 insertions, 6 deletions

diff --git a/desktop/textarea.c b/desktop/textarea.c
index 5bae27a5c..e25c6335f 100644
--- a/desktop/textarea.c
+++ b/desktop/textarea.c
@@ -58,7 +58,7 @@ struct line_info {
 struct textarea_drag {
 	textarea_drag_type type;
 	union {
-		struct scrollbar* scrollbar;
+		struct scrollbar *scrollbar;
 	} data;
 };
 
@@ -625,7 +625,7 @@ static bool textarea_select(struct textarea *ta, int b_start, int b_end,
  * \param ta  Text area
  * \return True on success, false otherwise
  */
-static bool textarea_select_fragment(struct textarea * ta)
+static bool textarea_select_fragment(struct textarea *ta)
 {
 	int caret_pos;
 	size_t sel_start, sel_end;
@@ -676,7 +676,7 @@ static bool textarea_select_fragment(struct textarea * ta)
  * \param ta  textarea widget
  * \return True on success, false otherwise
  */
-static bool textarea_select_paragraph(struct textarea * ta)
+static bool textarea_select_paragraph(struct textarea *ta)
 {
 	int caret_pos;
 	size_t sel_start, sel_end;
@@ -1607,7 +1607,7 @@ static bool textarea_copy_to_undo_buffer(struct textarea *ta,
  * \param b_end		End byte index of replaced section (exclusive)
  * \param rep		Replacement UTF-8 text to insert
  * \param rep_len	Byte length of replacement UTF-8 text
- * \param add_to_clipboard	True iff replaced text to be added to clipboard
+ * \param add_to_clipboard	True if replaced text to be added to clipboard
  * \param byte_delta	Updated to change in byte count in textarea (ta->show)
  * \param r		Updated to area where redraw is required
  * \return false on memory exhaustion, true otherwise
@@ -2452,7 +2452,7 @@ bool textarea_keypress(struct textarea *ta, uint32_t key)
 	struct textarea_msg msg;
 	struct rect r;	/**< Redraw rectangle */
 	char utf8[6];
-	unsigned int caret, length, b_off, b_len;
+	unsigned int caret, caret_copy, length, b_off, b_len;
 	int h_extent = ta->h_extent;
 	int v_extent = ta->v_extent;
 	int line;
@@ -2466,7 +2466,7 @@ bool textarea_keypress(struct textarea *ta, uint32_t key)
 	/* Word separators */
 	static const char *sep = " .\n";
 
-	caret = textarea_get_caret(ta);
+	caret = caret_copy = textarea_get_caret(ta);
 	line = ta->caret_pos.line;
 	readonly = (ta->flags & TEXTAREA_READONLY ? true : false);
 
@@ -2760,6 +2760,50 @@ bool textarea_keypress(struct textarea *ta, uint32_t key)
 				textarea_clear_selection(ta);
 			}
 			break;
+		case NS_KEY_DELETE_WORD_LEFT:
+			if (readonly)
+				break;
+
+			/* If there is a selection, remove the selected
+			* characters */
+			if (ta->sel_start != -1) {
+				if (!textarea_replace_text(ta, ta->sel_start,
+						ta->sel_end, "", 0, false,
+						&byte_delta, &r))
+					return false;
+				caret = ta->sel_start;
+				textarea_clear_selection(ta);
+				redraw = true;
+				break;
+			}
+
+			if (caret == 0)
+				break;
+
+			/* caret goes left until a non-separator is
+			* encountered */
+			caret--;
+			while (strchr(sep, ta->show->data[caret]) != NULL &&
+					caret > 0)
+				caret--;
+
+			/* caret goes left until a separator is encountered */
+			for (; caret > 0; caret--) {
+				if (strchr(sep, ta->show->data[caret]) !=
+						NULL) {
+					caret++;
+					break;
+				}
+			}
+
+			/* Remove the characters from new caret position to
+			* original caret position */
+			if (!textarea_replace_text(ta, caret, caret_copy,
+					"", 0, false, &byte_delta, &r))
+				return false;
+
+			redraw = true;
+			break;
 		case NS_KEY_WORD_RIGHT:
 			if (readonly)
 				break;
@@ -2783,6 +2827,49 @@ bool textarea_keypress(struct textarea *ta, uint32_t key)
 				textarea_clear_selection(ta);
 			}
 			break;
+		case NS_KEY_DELETE_WORD_RIGHT:
+			if (readonly)
+				break;
+
+			/* If there is a selection, remove the selected
+			* characters */
+			if (ta->sel_start != -1) {
+				if (!textarea_replace_text(ta, ta->sel_start,
+						ta->sel_end, "", 0, false,
+						&byte_delta, &r))
+					return false;
+				caret = ta->sel_start;
+				textarea_clear_selection(ta);
+				redraw = true;
+				break;
+			}
+
+			if (caret == ta->show->len - 1)
+				break;
+
+			/* caret_copy goes right until a non-separator is
+			* encountered */
+			while (strchr(sep, ta->show->data[caret_copy]) != NULL
+					&& caret_copy < ta->show->len - 1)
+				caret_copy++;
+
+			/* caret_copy goes right until a separator is
+			* encountered */
+			for (; caret_copy < ta->show->len - 1; caret_copy++) {
+				if (strchr(sep, ta->show->data[caret_copy]) !=
+						NULL) {
+					break;
+				}
+			}
+
+			/* Remove all the characters from original caret
+			* position to caret_copy */
+			if (!textarea_replace_text(ta, caret, caret_copy,
+					"", 0, false, &byte_delta, &r))
+				return false;
+
+			redraw = true;
+			break;
 		case NS_KEY_DELETE_LINE:
 			if (readonly)
 				break;