Imported Upstream version 0.2+gitdfdad95upstream/0.2+gitdfdad95

1 files changed, 172 insertions, 0 deletions

diff --git a/src/gui/tipViewer.vala b/src/gui/tipViewer.vala
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+/* 
+Copyright (c) 2011 by Simon Schneegans
+
+This program is free software: you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the Free
+Software Foundation, either version 3 of the License, or (at your option)
+any later version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+more details.
+
+You should have received a copy of the GNU General Public License along with
+this program.  If not, see <http://www.gnu.org/licenses/>. 
+*/
+
+namespace GnomePie {
+
+/////////////////////////////////////////////////////////////////////////    
+/// A widget showing tips. The tips are beautifully faded in and out.
+/////////////////////////////////////////////////////////////////////////
+
+public class TipViewer : Gtk.Label {
+
+    /////////////////////////////////////////////////////////////////////
+    /// Some settings tweaking the behavior of the TipViewer.
+    /////////////////////////////////////////////////////////////////////
+
+    private const double fade_time = 0.5;
+    private const double frame_rate = 20.0;
+    private const double delay = 7.0;
+
+    /////////////////////////////////////////////////////////////////////
+    /// False, if the playback of tips is stopped.
+    /////////////////////////////////////////////////////////////////////
+    
+    private bool playing = false;
+    
+    /////////////////////////////////////////////////////////////////////
+    /// An array containing all tips.
+    /////////////////////////////////////////////////////////////////////
+    
+    private string[] tips;
+    
+    /////////////////////////////////////////////////////////////////////
+    /// The index of the currently displayed tip.
+    /////////////////////////////////////////////////////////////////////
+    
+    private int index = -1;
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Colors of the font and the background. Used for fading effects.
+    /////////////////////////////////////////////////////////////////////
+    
+    private Gdk.Color fg;
+    private Gdk.Color bg;
+    
+    /////////////////////////////////////////////////////////////////////
+    /// The fading value.
+    /////////////////////////////////////////////////////////////////////
+    
+    private AnimatedValue alpha;
+    
+    /////////////////////////////////////////////////////////////////////
+    /// C'tor, initializes all members and sets the basic layout.
+    /////////////////////////////////////////////////////////////////////
+    
+    public TipViewer(string[] tips) {
+        this.tips = tips;
+        this.fg = this.get_style().fg[0];
+        this.bg = this.get_style().bg[0];
+        
+        this.alpha = new AnimatedValue.linear(1.0, 0.0, this.fade_time);
+        
+        this.set_alignment (0.0f, 0.5f);
+        this.wrap = true;
+        this.set_use_markup(true);
+        this.modify_font(Pango.FontDescription.from_string("9"));
+        
+        this.set_random_tip();
+    }
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Starts the playback of tips.
+    /////////////////////////////////////////////////////////////////////
+    
+    public void start_slide_show() {
+        if (!this.playing && tips.length > 1) {
+            this.playing = true;
+            GLib.Timeout.add((uint)(this.delay*1000.0), () => {
+                this.fade_out();
+                
+                GLib.Timeout.add((uint)(1000.0*this.fade_time), () => {
+                    this.set_random_tip();
+                    this.fade_in();
+                    return false;
+                });
+                
+                return this.playing;
+            });
+        }
+    }
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Stops the playback of tips.
+    /////////////////////////////////////////////////////////////////////
+    
+    public void stop_slide_show() {
+        this.playing = false;
+    }
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Starts the fading in.
+    /////////////////////////////////////////////////////////////////////
+    
+    private void fade_in() {
+        this.alpha = new AnimatedValue.linear(this.alpha.val, 1.0, this.fade_time);
+        
+        GLib.Timeout.add((uint)(1000.0/this.frame_rate), () => {
+            this.alpha.update(1.0/this.frame_rate);
+            this.update_label();
+            
+            return (this.alpha.val != 1.0);
+        });
+    }
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Starts the fading out.
+    /////////////////////////////////////////////////////////////////////
+    
+    private void fade_out() {
+        this.alpha = new AnimatedValue.linear(this.alpha.val, 0.0, this.fade_time);
+        
+        GLib.Timeout.add((uint)(1000.0/this.frame_rate), () => {
+            this.alpha.update(1.0/this.frame_rate);
+            this.update_label();
+            
+            return (this.alpha.val != 0.0);
+        });
+    }
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Updates the color of the label. Called every frame while fading.
+    /////////////////////////////////////////////////////////////////////
+    
+    private void update_label() {
+        Gdk.Color color = {(uint32)(fg.pixel*this.alpha.val + bg.pixel*(1.0 - this.alpha.val)),
+                           (uint16)(fg.red*this.alpha.val + bg.red*(1.0 - this.alpha.val)),
+                           (uint16)(fg.green*this.alpha.val + bg.green*(1.0 - this.alpha.val)),
+                           (uint16)(fg.blue*this.alpha.val + bg.blue*(1.0 - this.alpha.val))};
+        
+        this.modify_fg(Gtk.StateType.NORMAL, color);
+    }
+    
+    /////////////////////////////////////////////////////////////////////
+    /// Chooses the next random tip.
+    /////////////////////////////////////////////////////////////////////
+    
+    private void set_random_tip() {
+        if (tips.length > 1) {
+            int next_index = -1;
+            do {
+                next_index = GLib.Random.int_range(0, tips.length);
+            } while (next_index == this.index);
+            this.index = next_index;
+            this.label = tips[this.index];
+        }
+    }
+}
+
+}