From 090bbf2b77284b5fa35197f0bfc96945889bf978 Mon Sep 17 00:00:00 2001
From: Patrick McDermott <pj@pehjota.net>
Date: Thu, 21 Sep 2017 19:33:50 -0400
Subject: MqTabChrome: Explain hardcoded GtkScrolledWindow sizes

---
(limited to 'src')

diff --git a/src/tab-chrome.c b/src/tab-chrome.c
index 3ca8df2..a9391db 100644
--- a/src/tab-chrome.c
+++ b/src/tab-chrome.c
@@ -201,6 +201,41 @@ back_forward_box_button_press_cb(GtkWidget *widget, GdkEvent *event,
 		++chrome->back_items;
 	}
 
+	/*
+	 * The following GtkScrolledWindow widgets have hardcoded minimum sizes,
+	 * because there seems to be (in GTK+ versions before 3.22) no way to
+	 * set the natural size of GtkScrolledWindow and its GtkViewport.
+	 *
+	 * I tried:
+	 *
+	 *   - Setting size requests of the sizes of child widgets plus
+	 *     scrollbars (commit 2205669)
+	 *   - Putting GtkScrolledWindow widgets in stacks with non-scrolled
+	 *     versions of children, to allocate more area for the
+	 *     GtkScrolledWindow widgets to fill (commits 922cdef and 90686fa)
+	 *   - Setting policies to disable scrollbars upon GtkScrolledWindow
+	 *     instantiation, then enabling scrollbars on the GtkScrolledWindow
+	 *     "size-allocate" signal (commits c534c7e and 42ca783)
+	 *
+	 * Attempts to match the size of a GtkScrolledWindow's GtkViewport to
+	 * its child's size don't allow the GtkScrolledWindow and GtkViewport to
+	 * shrink when necessary to fit within the window.  Therefore, such
+	 * methods are equivalent to simply not using GtkScrolledWindow at all.
+	 * And there appears to be no easy way to calculate the available size
+	 * (the size of the GtkWindow minus all of the surrounding widgets) to
+	 * manually manage a GtkViewport's size.
+	 *
+	 * GtkScrolledWindow or GtkViewport ignores the child's preferred
+	 * (minimum and natural) sizes and apparently just sets a hardcoded size
+	 * of about 64x64 px.  I considered subclassing GtkScrolledWindow or
+	 * GtkViewport, but I'm not sure where the hardcoded size is set.
+	 *
+	 * The functions gtk_scrolled_window_set_propagate_natural_width() and
+	 * gtk_scrolled_window_set_propagate_natural_height() were introduced in
+	 * GTK+ 3.22 and probably do what I want.  However, I want to maintain
+	 * compatibility with at least GTK+ 3.12 or 3.14.
+	 */
+
 	/* Set up the list scrolled window. */
 	list_scrolled_window = gtk_scrolled_window_new(NULL, NULL);
 	gtk_scrolled_window_set_min_content_width(
--
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