- add listbox

 - add listbox example to python (press space, use 1..5)
 - fix label text positions

1 files changed, 261 insertions, 0 deletions

diff --git a/lib/gui/elistbox.cpp b/lib/gui/elistbox.cpp
new file mode 100644
index 00000000..c2af3d32
--- /dev/null
+++ b/lib/gui/elistbox.cpp
@@ -0,0 +1,261 @@
+#include <lib/gui/elistbox.h>
+
+/*
+    The basic idea is to have an interface which gives all relevant list
+    processing functions, and can be used by the listbox to browse trough
+    the list.
+    
+    The listbox directly uses the implemented cursor. It tries hard to avoid
+    iterating trough the (possibly very large) list, so it should be O(1),
+    i.e. the performance should not be influenced by the size of the list.
+    
+    The list interface knows how to draw the current entry to a specified 
+    offset. Different interfaces can be used to adapt different lists,
+    pre-filter lists on the fly etc.
+    
+		cursorSave/Restore is used to avoid re-iterating the list on redraw.
+		The current selection is always selected as cursor position, the
+    cursor is then positioned to the start, and then iterated. This gives
+    at most 2x m_items_per_page cursor movements per redraw, indepenent
+    of the size of the list.
+    
+    Although cursorSet is provided, it should be only used when there is no
+    other way, as it involves iterating trough the list.
+ */
+
+class eListboxTestContent: public virtual iListboxContent
+{
+	DECLARE_REF;
+public:
+	void cursorHome();
+	void cursorEnd();
+	int cursorMove(int count=1);
+	int cursorValid();
+	int cursorSet(int n);
+	int cursorGet();
+	
+	void cursorSave();
+	void cursorRestore();
+	int size();
+	
+	RESULT connectItemChanged(const Slot0<void> &itemChanged, ePtr<eConnection> &connection);
+	
+	// void setOutputDevice ? (for allocating colors, ...) .. requires some work, though
+	void setSize(const eSize &size);
+	
+		/* the following functions always refer to the selected item */
+	void paint(gPainter &painter, eWindowStyle &style, const ePoint &offset, int selected);
+private:
+	int m_cursor, m_saved_cursor;
+	eSize m_size;
+};
+
+DEFINE_REF(eListboxTestContent);
+
+void eListboxTestContent::cursorHome()
+{
+	m_cursor = 0;
+}
+
+void eListboxTestContent::cursorEnd()
+{
+	m_cursor = size();
+}
+
+int eListboxTestContent::cursorMove(int count)
+{
+	m_cursor += count;
+	
+	if (m_cursor < 0)
+		cursorHome();
+	else if (m_cursor > size())
+		cursorEnd();
+	return 0;
+}
+
+int eListboxTestContent::cursorValid()
+{
+	return m_cursor < size();
+}
+
+int eListboxTestContent::cursorSet(int n)
+{
+	m_cursor = n;
+	
+	if (m_cursor < 0)
+		cursorHome();
+	else if (m_cursor > size())
+		cursorEnd();
+	return 0;
+}
+
+int eListboxTestContent::cursorGet()
+{
+	return m_cursor;
+}
+
+void eListboxTestContent::cursorSave()
+{
+	m_saved_cursor = m_cursor;
+}
+
+void eListboxTestContent::cursorRestore()
+{
+	m_cursor = m_saved_cursor;
+}
+
+int eListboxTestContent::size()
+{
+	return 10;
+}
+	
+RESULT eListboxTestContent::connectItemChanged(const Slot0<void> &itemChanged, ePtr<eConnection> &connection)
+{
+	return 0;
+}
+
+void eListboxTestContent::setSize(const eSize &size)
+{
+	m_size = size;
+}
+
+void eListboxTestContent::paint(gPainter &painter, eWindowStyle &style, const ePoint &offset, int selected)
+{
+	ePtr<gFont> fnt = new gFont("Arial", 14);
+	painter.clip(eRect(offset, m_size));
+	style.setStyle(painter, selected ? eWindowStyle::styleListboxSelected : eWindowStyle::styleListboxNormal);
+	painter.clear();
+
+	if (cursorValid())
+	{
+		painter.setFont(fnt);
+		char string[10];
+		sprintf(string, "%d.)", m_cursor);
+		
+		ePoint text_offset = offset + (selected ? ePoint(2, 2) : ePoint(1, 1));
+		
+		painter.renderText(eRect(text_offset, m_size), string);
+		
+		if (selected)
+			style.drawFrame(painter, eRect(offset, m_size), eWindowStyle::frameListboxEntry);
+	}
+	
+	painter.clippop();
+}
+
+eListbox::eListbox(eWidget *parent): eWidget(parent)
+{
+	setContent(new eListboxTestContent());
+	m_content->cursorHome();
+	m_top = 0;
+	m_selected = 0;
+}
+
+void eListbox::setContent(iListboxContent *content)
+{
+	m_content = content;
+}
+
+void eListbox::moveSelection(int dir)
+{
+		/* we need the old top/sel to see what we have to redraw */
+	int oldtop = m_top;
+	int oldsel = m_selected;
+	
+		/* first, move cursor */
+	switch (dir)
+	{
+	case moveUp:
+		m_content->cursorMove(-1);
+		break;
+	case moveDown:
+		m_content->cursorMove(1);
+			/* ok - we could have reached the end. we just go one back then. */
+		if (!m_content->cursorValid())
+			m_content->cursorMove(-1);
+		break;
+	case moveTop:
+		m_content->cursorHome();
+		m_top = 0; /* align with top, speeds up process */
+		break;
+	case moveEnd:
+			/* move to last existing one ("end" is already invalid) */
+		m_content->cursorEnd(); m_content->cursorMove(-1); 
+		
+		m_top = m_content->cursorGet() - m_items_per_page + 1;
+		if (m_top < 0)
+			m_top = 0;
+		break;
+	}
+	
+		/* note that we could be on an invalid cursor position, but we don't
+		   care. this only happens on empty lists, and should have almost no
+		   side effects. */
+	
+		/* now, look wether the current selection is out of screen */
+	m_selected = m_content->cursorGet();
+	if (m_selected < m_top)
+	{
+		m_top -= m_items_per_page;
+		if (m_top < 0)
+			m_top = 0;
+	} else if (m_selected >= m_top + m_items_per_page)
+	{
+			/* m_top should be always valid here as it's selected */
+		m_top += m_items_per_page;
+	}
+	
+	if (m_top != oldtop)
+		invalidate();
+	else
+	{
+			/* redraw the old and newly selected */
+		gRegion inv = eRect(0, m_itemheight * (m_selected-m_top), size().width(), m_itemheight);
+		inv |= eRect(0, m_itemheight * (oldsel-m_top), size().width(), m_itemheight);
+		
+		invalidate(inv);
+	}
+}
+
+int eListbox::event(int event, void *data, void *data2)
+{
+	switch (event)
+	{
+	case evtPaint:
+	{
+		ePtr<eWindowStyle> style;
+		
+		assert(m_content);
+		recalcSize(); // move to event
+		
+		getStyle(style);
+		
+		if (!m_content)
+			return 0;
+		
+		gPainter &painter = *(gPainter*)data2;
+		
+		m_content->cursorSave();
+		m_content->cursorMove(m_top - m_selected);
+		
+		for (int y = 0, i = 0; i < m_items_per_page; y += m_itemheight, ++i)
+		{
+			m_content->paint(painter, *style, ePoint(0, y), m_selected == m_content->cursorGet());
+			m_content->cursorMove(+1);
+		}
+		
+		m_content->cursorRestore();
+		
+		return 0;
+	}
+	default:
+		return eWidget::event(event, data, data2);
+	}
+}
+
+void eListbox::recalcSize()
+{
+	m_itemheight = 20;
+	m_content->setSize(eSize(size().width(), m_itemheight));
+	m_items_per_page = size().height() / m_itemheight;
+}