[rhythmbox] header: degrade gracefully when reduced in size

[Jonathan Matthew <jmatthew src gnome org>]

commit 34fab57a05403e021501c362a921ebdeb470d424
Author: Jonathan Matthew <jonathan d14n org>
Date:   Thu Mar 29 20:37:18 2012 +1000

    header: degrade gracefully when reduced in size
    
    Rather than vanishing when the widgets within the header don't
    have enough space, hide things to make the remaining stuff fit.
    First the song info disappears, then the elapsed time, then the
    position slider.

 widgets/rb-header.c |   96 ++++++++++++++++++++++++++++++++++++++-------------
 1 files changed, 72 insertions(+), 24 deletions(-)
---
diff --git a/widgets/rb-header.c b/widgets/rb-header.c
index c62539f..044886d 100644
--- a/widgets/rb-header.c
+++ b/widgets/rb-header.c
@@ -73,6 +73,10 @@ static void rb_header_get_property (GObject *object,
 				    guint prop_id,
 				    GValue *value,
 				    GParamSpec *pspec);
+static GtkSizeRequestMode rb_header_get_request_mode (GtkWidget *widget);
+static void rb_header_get_preferred_width (GtkWidget *widget,
+					   int *minimum_size,
+					   int *natural_size);
 static void rb_header_size_allocate (GtkWidget *widget, GtkAllocation *allocation);
 static void rb_header_update_elapsed (RBHeader *header);
 static void apply_slider_position (RBHeader *header);
@@ -120,6 +124,8 @@ struct RBHeaderPrivate
 	long duration;
 	gboolean seekable;
 	char *image_path;
+	gboolean show_album_art;
+	gboolean show_slider;
 };
 
 enum
@@ -159,7 +165,10 @@ rb_header_class_init (RBHeaderClass *klass)
 	object_class->set_property = rb_header_set_property;
 	object_class->get_property = rb_header_get_property;
 
+	widget_class->get_request_mode = rb_header_get_request_mode;
+	widget_class->get_preferred_width = rb_header_get_preferred_width;
 	widget_class->size_allocate = rb_header_size_allocate;
+	/* GtkGrid's get_preferred_height_for_width does all we need here */
 
 	/**
 	 * RBHeader:db:
@@ -447,6 +456,21 @@ rb_header_playing_song_changed_cb (RBShellPlayer *player, RhythmDBEntry *entry,
 	rb_fading_image_start (RB_FADING_IMAGE (header->priv->image), 2000);
 }
 
+static GtkSizeRequestMode
+rb_header_get_request_mode (GtkWidget *widget)
+{
+	return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
+}
+
+static void
+rb_header_get_preferred_width (GtkWidget *widget,
+			       int *minimum_width,
+			       int *natural_width)
+{
+	*minimum_width = 0;
+	*natural_width = 0;
+}
+
 static void
 rb_header_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
 {
@@ -463,7 +487,7 @@ rb_header_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
 	rtl = (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL);
 
 	/* take some leading space for the image, which we always make square */
-	if (gtk_widget_get_visible (RB_HEADER (widget)->priv->image)) {
+	if (RB_HEADER (widget)->priv->show_album_art) {
 		image_width = allocation->height;
 		if (rtl) {
 			child_alloc.x = allocation->x + allocation->width - image_width;
@@ -477,26 +501,36 @@ rb_header_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
 		child_alloc.width = image_width;
 		child_alloc.height = allocation->height;
 		gtk_widget_size_allocate (RB_HEADER (widget)->priv->image, &child_alloc);
+	} else {
+		image_width = 0;
 	}
 
 	/* figure out how much space to allocate to the scale.
 	 * it gets at least its minimum size, at most 1/3 of the
 	 * space we have.
 	 */
-	if (gtk_widget_get_visible (RB_HEADER (widget)->priv->scale)) {
+	if (RB_HEADER (widget)->priv->show_slider) {
 		gtk_widget_get_preferred_width (RB_HEADER (widget)->priv->scale, &scale_width, NULL);
 		if (scale_width < allocation->width / 3)
 			scale_width = allocation->width / 3;
 
-		if (rtl) {
-			child_alloc.x = allocation->x;
+		if (scale_width + image_width > allocation->width)
+			scale_width = allocation->width - image_width;
+
+		if (scale_width > 0) {
+			if (rtl) {
+				child_alloc.x = allocation->x;
+			} else {
+				child_alloc.x = allocation->x + (allocation->width - scale_width) + spacing;
+			}
+			child_alloc.y = allocation->y;
+			child_alloc.width = scale_width - spacing;
+			child_alloc.height = allocation->height;
+			gtk_widget_show (RB_HEADER (widget)->priv->scale);
+			gtk_widget_size_allocate (RB_HEADER (widget)->priv->scale, &child_alloc);
 		} else {
-			child_alloc.x = allocation->x + (allocation->width - scale_width) + spacing;
+			gtk_widget_hide (RB_HEADER (widget)->priv->scale);
 		}
-		child_alloc.y = allocation->y;
-		child_alloc.width = scale_width - spacing;
-		child_alloc.height = allocation->height;
-		gtk_widget_size_allocate (RB_HEADER (widget)->priv->scale, &child_alloc);
 	} else {
 		scale_width = 0;
 	}
@@ -512,20 +546,32 @@ rb_header_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
 	} else {
 		child_alloc.x = allocation->x;
 	}
-	child_alloc.y = allocation->y;
-	child_alloc.width = info_width;
-	child_alloc.height = allocation->height;
-	gtk_widget_size_allocate (RB_HEADER (widget)->priv->songbox, &child_alloc);
 
-	if (rtl) {
-		child_alloc.x = allocation->x + scale_width + spacing;
+	if (info_width > 0) {
+		child_alloc.y = allocation->y;
+		child_alloc.width = info_width;
+		child_alloc.height = allocation->height;
+		gtk_widget_show (RB_HEADER (widget)->priv->songbox);
+		gtk_widget_size_allocate (RB_HEADER (widget)->priv->songbox, &child_alloc);
 	} else {
-		child_alloc.x = allocation->x + info_width + spacing;
+		gtk_widget_hide (RB_HEADER (widget)->priv->songbox);
+		info_width = 0;
+	}
+
+	if (info_width + scale_width + (2 * spacing) + time_width > allocation->width) {
+		gtk_widget_hide (RB_HEADER (widget)->priv->timebutton);
+	} else {
+		if (rtl) {
+			child_alloc.x = allocation->x + scale_width + spacing;
+		} else {
+			child_alloc.x = allocation->x + info_width + spacing;
+		}
+		child_alloc.y = allocation->y;
+		child_alloc.width = time_width;
+		child_alloc.height = allocation->height;
+		gtk_widget_show (RB_HEADER (widget)->priv->timebutton);
+		gtk_widget_size_allocate (RB_HEADER (widget)->priv->timebutton, &child_alloc);
 	}
-	child_alloc.y = allocation->y;
-	child_alloc.width = time_width;
-	child_alloc.height = allocation->height;
-	gtk_widget_size_allocate (RB_HEADER (widget)->priv->timebutton, &child_alloc);
 }
 
 static void
@@ -563,10 +609,12 @@ rb_header_set_property (GObject *object,
 		rb_header_update_elapsed (header);
 		break;
 	case PROP_SHOW_POSITION_SLIDER:
-		gtk_widget_set_visible (header->priv->scale, g_value_get_boolean (value));
+		header->priv->show_slider = g_value_get_boolean (value);
+		gtk_widget_set_visible (header->priv->scale, header->priv->show_slider);
 		break;
 	case PROP_SHOW_ALBUM_ART:
-		gtk_widget_set_visible (header->priv->image, g_value_get_boolean (value));
+		header->priv->show_album_art = g_value_get_boolean (value);
+		gtk_widget_set_visible (header->priv->image, header->priv->show_album_art);
 		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
@@ -599,10 +647,10 @@ rb_header_get_property (GObject *object,
 		g_value_set_boolean (value, header->priv->show_remaining);
 		break;
 	case PROP_SHOW_POSITION_SLIDER:
-		g_value_set_boolean (value, gtk_widget_get_visible (header->priv->scale));
+		g_value_set_boolean (value, header->priv->show_slider);
 		break;
 	case PROP_SHOW_ALBUM_ART:
-		g_value_set_boolean (value, gtk_widget_get_visible (header->priv->image));
+		g_value_set_boolean (value, header->priv->show_album_art);
 		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);