GUI: Introduce dynamic layouts

Prior to this change, a GUI layout was only affected by the screen size.
Now, a layout can additionally be influenced by the GUI dialog and widgets
that uses it. This capability is leveraged to implement the following
features:

* Layout elements that are not bound to a GUI widget do not take space.
   This means that dialogs where the widgets shown depend on for example
   a feature being enabled at configure time no longer have blank spaces.
* Widgets can define a minimal required size for their contents not to be
   cut. For now this is only used for buttons so their width is always
   sufficient for their caption not to be cut. This mechanism could be
   applied to other widget types in the future.

1 files changed, 16 insertions, 19 deletions

diff --git a/gui/ThemeEval.cpp b/gui/ThemeEval.cpp
index 5255587089..66b5db5fb7 100644
--- a/gui/ThemeEval.cpp
+++ b/gui/ThemeEval.cpp
@@ -105,30 +105,18 @@ void ThemeEval::addWidget(const Common::String &name, int w, int h, const Common
 									typeAlign == Graphics::kTextAlignInvalid ? align : typeAlign);
 
 	_curLayout.top()->addChild(widget);
-	setVar(_curDialog + "." + name + ".Enabled", enabled ? 1 : 0);
+	setVar("Dialog." + _curDialog + "." + name + ".Enabled", enabled ? 1 : 0);
 }
 
 void ThemeEval::addDialog(const Common::String &name, const Common::String &overlays, bool enabled, int inset) {
-	int16 x, y;
-	uint16 w, h;
+	Common::String var = "Dialog." + name;
 
-	ThemeLayout *layout = 0;
-
-	if (overlays == "screen") {
-		layout = new ThemeLayoutMain(inset, inset, g_system->getOverlayWidth() - 2 * inset, g_system->getOverlayHeight() - 2 * inset);
-	} else if (overlays == "screen_center") {
-		layout = new ThemeLayoutMain(-1, -1, -1, -1);
-	} else if (getWidgetData(overlays, x, y, w, h)) {
-		layout = new ThemeLayoutMain(x + inset, y + inset, w - 2 * inset, h - 2 * inset);
-	}
-
-	if (!layout)
-		error("Error when loading dialog position for '%s'", overlays.c_str());
+	ThemeLayout *layout = new ThemeLayoutMain(name, overlays, enabled, inset);
 
-	if (_layouts.contains(name))
-		delete _layouts[name];
+	if (_layouts.contains(var))
+		delete _layouts[var];
 
-	_layouts[name] = layout;
+	_layouts[var] = layout;
 
 	layout->setPadding(
 		getVar("Globals.Padding.Left", 0),
@@ -139,7 +127,7 @@ void ThemeEval::addDialog(const Common::String &name, const Common::String &over
 
 	_curLayout.push(layout);
 	_curDialog = name;
-	setVar(name + ".Enabled", enabled ? 1 : 0);
+	setVar(var + ".Enabled", enabled ? 1 : 0);
 }
 
 void ThemeEval::addLayout(ThemeLayout::LayoutType type, int spacing, bool center) {
@@ -168,6 +156,15 @@ void ThemeEval::addSpace(int size) {
 	_curLayout.top()->addChild(space);
 }
 
+void ThemeEval::reflowDialogLayout(const Common::String &name, Widget *widgetChain) {
+	if (!_layouts.contains("Dialog." + name)) {
+		warning("No layout found for dialog '%s'", name.c_str());
+		return;
+	}
+
+	_layouts["Dialog." + name]->reflowLayout(widgetChain);
+}
+
 bool ThemeEval::addImportedLayout(const Common::String &name) {
 	if (!_layouts.contains(name))
 		return false;