From 0373ef13952db1b55f37578994da69f92326bf10 Mon Sep 17 00:00:00 2001
From: Enrico Zini <enrico@enricozini.org>
Date: Mon, 14 Dec 2009 17:34:39 +0000
Subject: [PATCH] Show prefixes on the right

---
 gtkfisheyelist/gtkfisheyelistview.vala | 76 ++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/gtkfisheyelist/gtkfisheyelistview.vala b/gtkfisheyelist/gtkfisheyelistview.vala
index af2673f..dc49c73 100644
--- a/gtkfisheyelist/gtkfisheyelistview.vala
+++ b/gtkfisheyelist/gtkfisheyelistview.vala
@@ -26,6 +26,41 @@ protected struct FocusInfo
 	int renderer;
 }
 
+protected class PrefixInfo
+{
+	public string prefix;
+	public size_t pfx_len;
+	public int pos;
+	public int layout_pos;
+
+	public PrefixInfo(string prefix, int pos)
+	{
+		this.prefix = prefix;
+		this.pfx_len = prefix.size();
+		this.pos = pos;
+		this.layout_pos = 0;
+	}
+
+	/**
+	 * If s and prefix share a prefix, set prefix to the common prefix, and
+	 * return true.
+	 * Else, return false.
+	 */
+	public bool refine(string s)
+	{
+		size_t len;
+		for (len = 0; prefix[len] != 0 && s[len] != 0 && s[len] == prefix[len]; ++len)
+			;
+		if (len == 0) return false;
+		if (len != pfx_len)
+		{
+			prefix = prefix.substring(0, (int)len);
+			pfx_len = len;
+		}
+		return true;
+	}
+}
+
 public class FisheyeListView : Gtk.DrawingArea
 {
 	protected Gtk.TreeModel model;
@@ -42,6 +77,9 @@ public class FisheyeListView : Gtk.DrawingArea
 	protected string[] label_cache;
 	protected bool base_layout_needed;
 
+	// Prefix information
+	protected List<PrefixInfo> prefixes;
+
 	protected int cur_el;
 
 	// Layout information
@@ -85,6 +123,7 @@ public class FisheyeListView : Gtk.DrawingArea
 		backing_store = null;
 
 		label_cache = null;
+		prefixes = null;
 
 		renderers = new Gtk.CellRendererText[steps];
 		renderer_sizes = new int[steps];
@@ -235,6 +274,7 @@ public class FisheyeListView : Gtk.DrawingArea
 	protected void base_layout()
 	{
 		// Rebuild label cache
+		prefixes = new List<PrefixInfo>();
 		if (model == null)
 		{
 			label_cache = new string[0];
@@ -250,14 +290,23 @@ public class FisheyeListView : Gtk.DrawingArea
 				label_cache = new string[count];
 
 				int i = 0;
+				PrefixInfo pi = null;
 				do {
 					string val;
 					model.get(iter, _label_column, out val, -1);
 					label_cache[i] = val;
+					if (pi == null || !pi.refine(val))
+					{
+						if (pi != null) prefixes.append(pi);
+						pi = new PrefixInfo(val, i);
+					}
 					++i;
 				} while (model.iter_next(ref iter));
+				prefixes.append(pi);
 			}
 		}
+		for (weak List<PrefixInfo> i = prefixes; i != null; i = i.next)
+			i.data.layout_pos = i.data.pos * allocation.height / (label_cache.length+1);
 
 		background = new Gdk.Pixmap(window, allocation.width, allocation.height, -1);
 		backing_store = new Gdk.Pixmap(window, allocation.width, allocation.height, -1);
@@ -386,6 +435,7 @@ public class FisheyeListView : Gtk.DrawingArea
 				allocation.width/2, allocation.height-y-30, allocation.width/2, 10);
 		}
 
+		// Draw tiny labels
 		Gdk.Rectangle expose_area = Gdk.Rectangle();
 		expose_area.x = expose_area.y = 0;
 		expose_area.width = allocation.width;
@@ -429,6 +479,32 @@ public class FisheyeListView : Gtk.DrawingArea
 						0);
 			}
 		}
+
+		// Draw prefix labels
+		Pango.Layout layout = create_pango_layout(null);
+		Pango.Rectangle lr;
+		layout.get_extents(null, out lr);
+		int label_height = lr.height / Pango.SCALE;
+		layout.set_alignment(Pango.Alignment.RIGHT);
+		layout.set_width(allocation.width*Pango.SCALE/3);
+		layout.set_height(0);
+//stderr.printf("HEIGHT %d+%d = %d\n", lr.y, lr.height, lr.y + lr.height);
+		//layout.set_wrap(Pango.WrapMode.
+		layout.set_ellipsize(Pango.EllipsizeMode.END);
+
+		int last_covered = 0;
+
+		for (weak List<PrefixInfo> i = prefixes; i != null; i = i.next)
+		{
+stderr.printf("DRAW %s at %d lc %d\n", i.data.prefix, i.data.layout_pos, last_covered);
+			if (i.data.layout_pos < last_covered)
+			{
+				i.data.layout_pos = last_covered;
+			}
+			layout.set_text(i.data.prefix, int.max(10, (int)i.data.pfx_len));
+			Gtk.paint_layout(style, (Gdk.Window*)drawable, Gtk.StateType.NORMAL, true, null, this, null, allocation.width*2/3, i.data.layout_pos, layout);
+			last_covered = i.data.layout_pos + label_height;
+		}
 	}
 
 	protected void draw()
-- 
2.39.5