From 130a23f483fe2e486e6d9d804b9d998c159fbcb0 Mon Sep 17 00:00:00 2001
From: Stijn Buys <ingar@osirion.org>
Date: Sun, 12 Feb 2012 12:12:53 +0000
Subject: Scroll listview content by item count instead of by height, enabled
 listview mousewheel scrolling.

---
 src/ui/listview.cc | 53 ++++++++++++++++++++++++++++++++++++++++++++++-------
 src/ui/listview.h  | 13 ++++++++++---
 2 files changed, 56 insertions(+), 10 deletions(-)

(limited to 'src')

diff --git a/src/ui/listview.cc b/src/ui/listview.cc
index 185b229..ac2a4e8 100644
--- a/src/ui/listview.cc
+++ b/src/ui/listview.cc
@@ -34,11 +34,18 @@ void ListView::set_scroll(float scroll)
 		listview_scroll = 0;
 	
 	// calculate maximal scroll size
-	float total_height = 0;
+	float nb_items = 0;
 	for (Children::iterator it = children().begin(); it != children().end(); it++) {
-		total_height += (*it)->height();
+		if ((*it) != static_cast<Widget *>(listview_scrollbar)) {
+			nb_items += 1.0f;
+		}	
+	}
+	if (nb_items > 0.0f) {
+		nb_items -= 1.0f;
+	}
+	if (listview_scroll > nb_items) {
+		listview_scroll = nb_items;
 	}
-	if (listview_scroll > total_height) listview_scroll = total_height;
 }
 
 void ListView::inc_scroll(float scroll)
@@ -57,28 +64,37 @@ void ListView::resize()
 	listview_scrollbar->set_location(width() - listview_scrollbar->width(), 0);
 	
 	float total_height = 0;
+	float visible_height = 0;
+	float nb_items = 0;
 	
 	// reposition all children within the container
 	for (Children::iterator it = children().begin(); it != children().end(); it++) {
 		if ((*it) != static_cast<Widget *>(listview_scrollbar)) {
 			(*it)->set_width(width() - listview_scrollbar->width());
-			if (total_height - listview_scroll < 0) {
+			
+			if (nb_items - listview_scroll < 0) {
 				// child widget is invisible
 				(*it)->hide();
-			} else if ((total_height - listview_scroll + (*it)->height()) > height()) {
+			} else if ((visible_height + (*it)->height()) > height()) {
 				// child widget is invisible
 				(*it)->hide();
 			} else {
+				// child widget is visible
 				(*it)->show();
-				(*it)->set_location(0, total_height - listview_scroll);
+				(*it)->set_location(0, visible_height);
+				visible_height += (*it)->height();
 			}
 			
 			total_height += (*it)->height();
+			nb_items += 1.0f;
+			
 		}
 	}
 	
 	if (total_height > height()) {
-		listview_scrollbar->set_range(0.0f, total_height - height());
+		if (nb_items > 0.0f)
+			nb_items -= 1.0f;
+		listview_scrollbar->set_range(0.0f, nb_items);
 		listview_scrollbar->set_value(listview_scroll);
 		listview_scrollbar->show();
 	} else {
@@ -134,6 +150,29 @@ bool ListView::on_emit(Widget *sender, const Event event, void *data)
 	return false;
 }
 
+bool ListView::on_keypress(const int key, const unsigned int modifier)
+{
+	switch (key) {
+		
+		case 512 + SDL_BUTTON_WHEELDOWN:
+			inc_scroll(1.0f);
+			resize();
+			return true;
+			break;
+		
+		case 512 + SDL_BUTTON_WHEELUP:
+			dec_scroll(1.0f);
+			resize();
+			return true;
+			break;
+			
+		default:
+			break;
+	}
+
+	return false;
+}
+
 bool compare_listitems(const Widget *first, const Widget *second)
 {
 	const ListItem *firstitem = dynamic_cast<const ListItem *>(first);
diff --git a/src/ui/listview.h b/src/ui/listview.h
index b097184..b4c00dc 100644
--- a/src/ui/listview.h
+++ b/src/ui/listview.h
@@ -64,22 +64,29 @@ public:
 	 * @brief sort child ListItems according to their sortkey
 	 * Sort will fail with an assert error if the ListView
 	 * contains any non-ListItem child widgets
-	 */
+	 * */
 	void sort();
 	
 	/**
 	 * @brief reverse sort child ListItems according to their sortkey
 	 * Sort will fail with an assert error if the ListView
 	 * contains any non-ListItem child widgets
-	 */
+	 * */
 	void sort_reverse();
 	
 protected:	
 	virtual void resize();
 	
-	/// emit event handler
+	/**
+	 * @brief emit event handler
+	 * */	
 	virtual bool on_emit(Widget *sender, const Event event, void *data);
 	
+	/**
+	 * @brief keypress event handler
+	 * */
+	virtual bool on_keypress(const int key, const unsigned int modifier);
+	
 private:
 	float		listview_scroll;
 	
-- 
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