Fix linear layouts to allow alignment.

layouts/linear.lisp

@@ -8,10 +8,20 @@
 
 (defclass linear-layout (layout)
   ((min-size :initarg :min-size :initform (size) :accessor min-size)
-   (stretch :initarg :stretch :initform T :accessor stretch)))
+   (stretch :initarg :stretch :initform T :accessor stretch)
+   (align :initarg :align :initform :start :accessor align)))
 
 (defgeneric update-linear-layout (layout index extent))
 
+(defmethod (setf align) :after (value (layout linear-layout))
+  (update-linear-layout layout 0 (bounds layout)))
+
+(defmethod (setf stretch) :after (value (layout linear-layout))
+  (update-linear-layout layout 0 (bounds layout)))
+
+(defmethod (setf min-size) :after (value (layout linear-layout))
+  (update-linear-layout layout 0 (bounds layout)))
+
 (defmethod notice-bounds :after ((element layout-element) (layout linear-layout))
   (let ((updated (update-linear-layout layout (element-index element layout) (bounds layout))))
     (unless (extent= (bounds layout) updated)
@@ -24,32 +34,44 @@
   ())
 
 (defmethod update-linear-layout ((layout vertical-linear-layout) index extent)
-  (destructure-extent (:x x :y oy :w w) extent
+  (destructure-extent (:x x :y oy :w w :h h) extent
     (let ((mh (size-h (min-size layout)))
           (mw (if (stretch layout) w (size-w (min-size layout))))
-          (y oy))
+          (y (ecase (align layout)
+               (:start oy) (:end (+ oy h)))))
       (do-elements (element layout :start index :result (extent x oy w (- y oy)))
         (let ((ideal (suggest-bounds (extent x y mw mh) element))
               (bounds (bounds element)))
           (setf (extent-x bounds) x)
-          (setf (extent-y bounds) y)
           (setf (extent-w bounds) (if (stretch layout) w (extent-w ideal)))
           (setf (extent-h bounds) (extent-h ideal))
-          (incf y (extent-h bounds)))))))
+          (ecase (align layout)
+            (:start
+             (setf (extent-y bounds) y)
+             (incf y (extent-h bounds)))
+            (:end
+             (decf y (extent-h bounds))
+             (setf (extent-y bounds) y))))))))
 
 (defclass horizontal-linear-layout (linear-layout)
   ())
 
 (defmethod update-linear-layout ((layout horizontal-linear-layout) index extent)
-  (destructure-extent (:x ox :y y :h h) extent
+  (destructure-extent (:x ox :y y :w w :h h) extent
     (let ((mh (if (stretch layout) h (size-h (min-size layout))))
           (mw (size-w (min-size layout)))
-          (x ox))
+          (x (ecase (align layout)
+               (:start ox) (:end (+ ox w)))))
       (do-elements (element layout :start index :result (extent ox y (- x ox) h))
         (let ((ideal (suggest-bounds (extent x y mw mh) element))
               (bounds (bounds element)))
-          (setf (extent-x bounds) x)
           (setf (extent-y bounds) y)
           (setf (extent-w bounds) (extent-w ideal))
           (setf (extent-h bounds) (if (stretch layout) h (extent-h ideal)))
-          (incf x (extent-w bounds)))))))
+          (ecase (align layout)
+            (:start
+             (setf (extent-x bounds) x)
+             (incf x (extent-w bounds)))
+            (:end
+             (decf x (extent-w bounds))
+             (setf (extent-x bounds) x))))))))