[project @ 2005-07-24 06:13:25 by adrianl]

Make selecting text easier by finding the nearest text above-left of the pointer; sort out issues with spaces in copied/saved text

svn path=/import/netsurf/; revision=1820

2 files changed, 136 insertions, 71 deletions

diff --git a/desktop/browser.c b/desktop/browser.c
index 5324ae984..7ab73fc6a 100644
--- a/desktop/browser.c
+++ b/desktop/browser.c
@@ -69,6 +69,7 @@ static void browser_radio_set(struct content *content,
 		struct form_control *radio);
 static gui_pointer_shape get_pointer_shape(css_cursor cursor);
 
+static struct box *browser_window_nearest_text_box(struct box *box, int x, int y);
 static struct box *browser_window_pick_text_box(struct browser_window *bw,
 		browser_mouse_state mouse, int x, int y, int *dx, int *dy);
 static void browser_window_page_drag_start(struct browser_window *bw, int x, int y);
@@ -745,6 +746,7 @@ void browser_window_mouse_action_html(struct browser_window *bw,
 	struct form_control *gadget = 0;
 	struct content *object = NULL;
 	url_func_result res;
+	struct box *next_box;
 
 	bw->drag_type = DRAGGING_NONE;
 	bw->scrolling_box = NULL;
@@ -753,8 +755,10 @@ void browser_window_mouse_action_html(struct browser_window *bw,
 	 * box with scrollbars */
 
 	box = c->data.html.layout;
-	while ((box = box_at_point(box, x, y, &box_x, &box_y, &content)) !=
+	while ((next_box = box_at_point(box, x, y, &box_x, &box_y, &content)) !=
 			NULL) {
+		box = next_box;
+
 		if (box->style &&
 				box->style->visibility == CSS_VISIBILITY_HIDDEN)
 			continue;
@@ -1622,6 +1626,42 @@ void browser_form_submit(struct browser_window *bw, struct form *form,
 
 
 /**
+ * Pick the text box child of 'box' that is closest to and above left of
+ * the point 'x,y'
+ *
+ * \param  box  parent box
+ * \param  x    x ordinate relative to parent box
+ * \param  y    y ordinate relative to parent box
+ * \return ptr to the nearest box, or NULL if none found
+ */
+
+struct box *browser_window_nearest_text_box(struct box *box, int x, int y)
+{
+	struct box *child = box->children;
+	struct box *nearest = NULL;
+	int nr_yd = INT_MAX;
+	int nr_xd = INT_MAX;
+
+	while (child) {
+		if (child->text && !child->object && child->y <= y && child->x <= x) {
+			int yd = y - (child->y + child->padding[TOP] + child->height + child->padding[BOTTOM]);
+			int xd = x - (child->x + child->padding[LEFT] + child->width + child->padding[RIGHT]);
+
+			/* give y displacement precedence of x */
+			if (yd < nr_yd || (yd == nr_yd && xd <= nr_xd)) {
+				nr_yd = yd;
+				nr_xd = xd;
+				nearest = child;
+			}
+		}
+		child = child->next;
+	}
+
+	return nearest;
+}
+
+
+/**
  * Peform pick text on browser window contents to locate the box under
  * the mouse pointer
  *
@@ -1639,29 +1679,41 @@ struct box *browser_window_pick_text_box(struct browser_window *bw,
 	struct content *c = bw->current_content;
 	struct box *text_box = NULL;
 
-	if (c) {
-		switch (c->type) {
-			case CONTENT_HTML: {
-				struct box *box = c->data.html.layout;
-				int box_x = 0, box_y = 0;
-				struct content *content;
+	if (c && c->type == CONTENT_HTML) {
+		struct box *box = c->data.html.layout;
+		int box_x = 0, box_y = 0;
+		struct content *content;
+		struct box *next_box;
 
-				while ((box = box_at_point(box, x, y, &box_x, &box_y, &content)) !=
-						NULL) {
+		while ((next_box = box_at_point(box, x, y, &box_x, &box_y, &content)) !=
+				NULL) {
+			box = next_box;
 
-					if (box->text && !box->object)
-						text_box = box;
-				}
+			if (box->text && !box->object)
+				text_box = box;
+		}
 
-				/* return coordinates relative to box */
-				*dx = x - box_x;
-				*dy = y - box_y;
-			}
-			break;
+		if (!text_box) {
+			box = browser_window_nearest_text_box(box, x - box_x, y - box_y);
 
-			default:
-				break;
+			if (box->text && !box->object) {
+
+				box_x += box->x - box->scroll_x;
+				box_y += box->y - box->scroll_y;
+
+				int y1 = box_y + (box->padding[TOP] + box->height + box->padding[BOTTOM]);
+				int x1 = box_x + (box->padding[LEFT] + box->width + box->padding[RIGHT]);
+
+				if (y > y1) y = y1;
+				if (x > x1) x = x1;
+
+				text_box = box;
+			}
 		}
+
+		/* return coordinates relative to box */
+		*dx = x - box_x;
+		*dy = y - box_y;
 	}
 
 	return text_box;
diff --git a/desktop/selection.c b/desktop/selection.c
index e72807d80..ea4b55ef1 100644
--- a/desktop/selection.c
+++ b/desktop/selection.c
@@ -42,6 +42,8 @@ static bool redraw_handler(struct box *box, int offset, size_t length, void *han
 static void selection_redraw(struct selection *s, unsigned start_idx, unsigned end_idx);
 static unsigned selection_label_subtree(struct selection *s, struct box *node, unsigned idx);
 static bool save_handler(struct box *box, int offset, size_t length, void *handle);
+static bool selected_part(struct box *box, unsigned start_idx, unsigned end_idx,
+		unsigned *start_offset, unsigned *end_offset);
 static bool traverse_tree(struct box *box, unsigned start_idx, unsigned end_idx,
 		seln_traverse_handler handler, void *handle);
 static struct box *get_box(struct box *b, unsigned offset, int *pidx);
@@ -181,10 +183,8 @@ unsigned selection_label_subtree(struct selection *s, struct box *node, unsigned
 
 	node->byte_offset = idx;
 
-	if (node->text && !node->object) {
-		idx += node->length;
-		if (node->space) idx++;
-	}
+	if (node->text && !node->object)
+		idx += node->length + node->space;
 
 	while (child) {
 		idx = selection_label_subtree(s, child, idx);
@@ -380,6 +380,56 @@ void selection_drag_end(struct selection *s, struct box *box,
 
 
 /**
+ * Tests whether a text box lies partially within the given range of
+ * byte offsets, returning the start and end indexes of the bytes
+ * that are enclosed.
+ *
+ * \param  box           box to be tested
+ * \param  start_idx     byte offset of start of range
+ * \param  end_idx       byte offset of end of range
+ * \param  start_offset  receives the start offset of the selected part
+ * \param  end_offset    receives the end offset of the selected part
+ * \return true iff the range encloses at least part of the box
+ */
+
+bool selected_part(struct box *box, unsigned start_idx, unsigned end_idx,
+		unsigned *start_offset, unsigned *end_offset)
+{
+	size_t box_length = box->length + box->space;
+
+	if (box->byte_offset >= start_idx &&
+		box->byte_offset + box_length <= end_idx) {
+
+		/* fully enclosed */
+		*start_offset = 0;
+		*end_offset = box_length;
+		return true;
+	}
+	else if (box->byte_offset + box_length > start_idx &&
+		box->byte_offset < end_idx) {
+		/* partly enclosed */
+		int offset = 0;
+		int len;
+
+		if (box->byte_offset < start_idx)
+			offset = start_idx - box->byte_offset;
+
+		len = box_length - offset;
+
+		if (box->byte_offset + box_length > end_idx)
+			len = end_idx - (box->byte_offset + offset);
+
+		*start_offset = offset;
+		*end_offset = offset + len;
+
+		return true;
+	}
+
+	return false;
+}
+
+
+/**
  * Traverse the given box subtree, calling the handler function (with its handle)
  * for all boxes that lie (partially) within the given range
  *
@@ -395,6 +445,7 @@ bool traverse_tree(struct box *box, unsigned start_idx, unsigned end_idx,
 		seln_traverse_handler handler, void *handle)
 {
 	struct box *child;
+	size_t box_length;
 
 	/* we can prune this subtree, it's after the selection */
 	assert(box);
@@ -404,31 +455,14 @@ bool traverse_tree(struct box *box, unsigned start_idx, unsigned end_idx,
 	/* read before calling the handler in case it modifies the tree */
 	child = box->children;
 
-	if (IS_TEXT(box) && box->length > 0) {
-
-		if (box->byte_offset >= start_idx &&
-			box->byte_offset + box->length <= end_idx) {
-			/* fully enclosed */
-			if (!handler(box, 0, box->length, handle))
-				return false;
-		}
-		else if (box->byte_offset + box->length >= start_idx &&
-			box->byte_offset < end_idx) {
-			/* partly enclosed */
-			int offset = 0;
-			int len;
-	
-			if (box->byte_offset < start_idx)
-				offset = start_idx - box->byte_offset;
-	
-			len = box->length - offset;
-	
-			if (box->byte_offset + box->length > end_idx)
-				len = end_idx - (box->byte_offset + offset);
+	box_length = box->length + box->space;  /* include trailing space */
+	if (IS_TEXT(box)) {
+		unsigned start_offset;
+		unsigned end_offset;
 
-			if (!handler(box, offset, len, handle))
+		if (selected_part(box, start_idx, end_idx, &start_offset, &end_offset) &&
+			!handler(box, start_offset, end_offset - start_offset, handle))
 				return false;
-		}
 	}
 	else {
 		/* make a guess at where the newlines should go */
@@ -756,34 +790,13 @@ bool selection_highlighted(struct selection *s, struct box *box,
 		unsigned *start_idx, unsigned *end_idx)
 {
 	/* caller should have checked first for efficiency */
+	assert(s);
 	assert(selection_defined(s));
-	assert(s && box);
 
-	if (box->length > 0) {
-		unsigned box_len = box->length + (box->space ? 1 : 0);
+	assert(box);
+	assert(IS_TEXT(box));
 
-		if (box->byte_offset < s->end_idx &&
-			box->byte_offset + box_len > s->start_idx) {
-			unsigned offset = 0;
-			unsigned len;
-	
-			if (box->byte_offset < s->start_idx)
-				offset = s->start_idx - box->byte_offset;
-	
-			len = box_len - offset;
-	
-			if (box->byte_offset + box_len > s->end_idx)
-				len = s->end_idx - (box->byte_offset + offset);
-	
-			assert(offset <= box_len);
-			assert(offset + len <= box->length + 1);
-	
-			*start_idx = offset;
-			*end_idx = offset + len;
-			return true;
-		}
-	}
-	return false;
+	return selected_part(box, s->start_idx, s->end_idx, start_idx, end_idx);
 }