Revising and fixing widget layout

Some of the logic for arranging widgets was invalid, leading to problems with the navbar:
- cannot resize children if own size depends on their size
- expanding children won't expand unless resizing all children

6 files changed, 182 insertions, 127 deletions

diff --git a/src/ui/lookupwidget.c b/src/ui/lookupwidget.c
index 7a0fe237..b06523f9 100644
--- a/src/ui/lookupwidget.c
+++ b/src/ui/lookupwidget.c
@@ -655,11 +655,10 @@ static iBool processEvent_LookupWidget_(iLookupWidget *d, const SDL_Event *ev) {
               equal_Rangecc(range_Command(cmd, "id"), "navbar"))) {
         /* Position the lookup popup under the URL bar. */ {
             iRoot *root = w->root;
-            const iInt2 rootSize = size_Root(root);
             const iRect navBarBounds = bounds_Widget(findChild_Widget(root->widget, "navbar"));
             iWidget *url = findChild_Widget(root->widget, "url");
             setFixedSize_Widget(w, init_I2(width_Widget(url),
-                                           (rootSize.y - bottom_Rect(navBarBounds)) / 2));
+                                           (bottom_Rect(rect_Root(root)) - bottom_Rect(navBarBounds)) / 2));
             setPos_Widget(w, windowToLocal_Widget(w, bottomLeft_Rect(bounds_Widget(url))));
 #if defined (iPlatformAppleMobile)
             /* Adjust height based on keyboard size. */ {
@@ -667,7 +666,7 @@ static iBool processEvent_LookupWidget_(iLookupWidget *d, const SDL_Event *ev) {
                 if (deviceType_App() == phone_AppDeviceType) {
                     float l, r;
                     safeAreaInsets_iOS(&l, NULL, &r, NULL);
-                    w->rect.size.x = rootSize.x - l - r;
+                    w->rect.size.x = size_Root(root).x - l - r;
                     w->rect.pos.x  = l;
                     /* TODO: Need to use windowToLocal_Widget? */
                 }
diff --git a/src/ui/root.c b/src/ui/root.c
index a97c8d49..287b641e 100644
--- a/src/ui/root.c
+++ b/src/ui/root.c
@@ -541,59 +541,63 @@ iBool isNarrow_Root(const iRoot *d) {
     return width_Rect(safeRect_Root(d)) / gap_UI < 140;
 }
 
-static iBool handleNavBarCommands_(iWidget *navBar, const char *cmd) {
-    if (equal_Command(cmd, "window.resized") || equal_Command(cmd, "metrics.changed")) {
-        const iBool isPhone = deviceType_App() == phone_AppDeviceType;
-        const iBool isNarrow = !isPhone && isNarrow_Root(navBar->root);
-        /* Adjust navbar padding. */ {
-            int hPad = isPhone && isPortrait_App() ? 0 : (isPhone || isNarrow) ? gap_UI / 2
-                                                                                 : gap_UI * 3 / 2;
-            int vPad = gap_UI * 3 / 2;
-            int topPad = !findWidget_App("winbar") ? gap_UI / 2 : 0;
-            setPadding_Widget(navBar, hPad, vPad / 3 + topPad, hPad, vPad / 2);
-        }
-        /* Button sizing. */
-        if (isNarrow ^ ((flags_Widget(navBar) & tight_WidgetFlag) != 0)) {
-            setFlags_Widget(navBar, tight_WidgetFlag, isNarrow);
-            iForEach(ObjectList, i, navBar->children) {
-                iWidget *child = as_Widget(i.object);
-                setFlags_Widget(child, tight_WidgetFlag, isNarrow);
-                if (isInstance_Object(i.object, &Class_LabelWidget)) {
-                    iLabelWidget *label = i.object;
-                    updateSize_LabelWidget(label);
-                }
+static void updateNavBarSize_(iWidget *navBar) {
+    const iBool isPhone = deviceType_App() == phone_AppDeviceType;
+    const iBool isNarrow = !isPhone && isNarrow_Root(navBar->root);
+    /* Adjust navbar padding. */ {
+        int hPad = isPhone && isPortrait_App() ? 0 : (isPhone || isNarrow) ? gap_UI / 2
+                                                                             : gap_UI * 3 / 2;
+        int vPad = gap_UI * 3 / 2;
+        int topPad = !findWidget_Root("winbar") ? gap_UI / 2 : 0;
+        setPadding_Widget(navBar, hPad, vPad / 3 + topPad, hPad, vPad / 2);
+    }
+    /* Button sizing. */
+    if (isNarrow ^ ((flags_Widget(navBar) & tight_WidgetFlag) != 0)) {
+        setFlags_Widget(navBar, tight_WidgetFlag, isNarrow);
+        iForEach(ObjectList, i, navBar->children) {
+            iWidget *child = as_Widget(i.object);
+            setFlags_Widget(child, tight_WidgetFlag, isNarrow);
+            if (isInstance_Object(i.object, &Class_LabelWidget)) {
+                iLabelWidget *label = i.object;
+                updateSize_LabelWidget(label);
             }
-            /* Note that InputWidget uses the `tight` flag to adjust its inner padding. */
-            /* TODO: Is this redundant? See `updateMetrics_Window_()`. */
-            const int embedButtonWidth = width_Widget(findChild_Widget(navBar, "navbar.lock"));
-            setContentPadding_InputWidget(findChild_Widget(navBar, "url"),
-                                          embedButtonWidth * 0.75f,
-                                          embedButtonWidth * 0.75f);
         }
-        if (isPhone) {
-            static const char *buttons[] = { "navbar.back",  "navbar.forward", "navbar.sidebar",
-                                             "navbar.ident", "navbar.home",    "navbar.menu" };
-            iWidget *toolBar = findWidget_App("toolbar");
-            setVisualOffset_Widget(toolBar, 0, 0, 0);
-            setFlags_Widget(toolBar, hidden_WidgetFlag, isLandscape_App());
-            iForIndices(i, buttons) {
-                iLabelWidget *btn = findChild_Widget(navBar, buttons[i]);
-                setFlags_Widget(as_Widget(btn), hidden_WidgetFlag, isPortrait_App());
-                if (isLandscape_App()) {
-                    /* Collapsing sets size to zero and the label doesn't know when to update
-                       its own size automatically. */
-                    updateSize_LabelWidget(btn);
-                }
+        /* Note that InputWidget uses the `tight` flag to adjust its inner padding. */
+        /* TODO: Is this redundant? See `updateMetrics_Window_()`. */
+        const int embedButtonWidth = width_Widget(findChild_Widget(navBar, "navbar.lock"));
+        setContentPadding_InputWidget(findChild_Widget(navBar, "url"),
+                                      embedButtonWidth * 0.75f,
+                                      embedButtonWidth * 0.75f);
+    }
+    if (isPhone) {
+        static const char *buttons[] = { "navbar.back",  "navbar.forward", "navbar.sidebar",
+                                         "navbar.ident", "navbar.home",    "navbar.menu" };
+        iWidget *toolBar = findWidget_App("toolbar");
+        setVisualOffset_Widget(toolBar, 0, 0, 0);
+        setFlags_Widget(toolBar, hidden_WidgetFlag, isLandscape_App());
+        iForIndices(i, buttons) {
+            iLabelWidget *btn = findChild_Widget(navBar, buttons[i]);
+            setFlags_Widget(as_Widget(btn), hidden_WidgetFlag, isPortrait_App());
+            if (isLandscape_App()) {
+                /* Collapsing sets size to zero and the label doesn't know when to update
+                   its own size automatically. */
+                updateSize_LabelWidget(btn);
             }
-            arrange_Widget(navBar->root->widget);
         }
-        /* Resize the URL input field. */ {
-            iWidget *urlBar = findChild_Widget(navBar, "url");
-            urlBar->rect.size.x = iMini(navBarAvailableSpace_(navBar), 167 * gap_UI);
-            arrange_Widget(navBar);
-        }
-        refresh_Widget(navBar);
-        postCommand_Widget(navBar, "layout.changed id:navbar");
+        arrange_Widget(navBar->root->widget);
+    }
+    /* Resize the URL input field. */ {
+        iWidget *urlBar = findChild_Widget(navBar, "url");
+        urlBar->rect.size.x = iMini(navBarAvailableSpace_(navBar), 167 * gap_UI);
+        arrange_Widget(navBar);
+    }
+    refresh_Widget(navBar);
+    postCommand_Widget(navBar, "layout.changed id:navbar");
+}
+
+static iBool handleNavBarCommands_(iWidget *navBar, const char *cmd) {
+    if (equal_Command(cmd, "window.resized") || equal_Command(cmd, "metrics.changed")) {
+        updateNavBarSize_(navBar);
         return iFalse;
     }
     else if (equal_Command(cmd, "window.reload.update")) {
@@ -740,16 +744,18 @@ static iBool handleSearchBarCommands_(iWidget *searchBar, const char *cmd) {
     else if (equal_Command(cmd, "focus.gained")) {
         if (pointer_Command(cmd) == findChild_Widget(searchBar, "find.input")) {
             if (!isVisible_Widget(searchBar)) {
-                setFlags_Widget(searchBar, hidden_WidgetFlag | disabled_WidgetFlag, iFalse);
-                arrange_Widget(root_Widget(searchBar));
-                postRefresh_App();
+//                setFlags_Widget(searchBar, hidden_WidgetFlag | disabled_WidgetFlag, iFalse);
+//                arrange_Widget(root_Widget(searchBar));
+//                postRefresh_App();
+                showCollapsed_Widget(searchBar, iTrue);
             }
         }
     }
     else if (equal_Command(cmd, "find.close")) {
         if (isVisible_Widget(searchBar)) {
-            setFlags_Widget(searchBar, hidden_WidgetFlag | disabled_WidgetFlag, iTrue);
-            arrange_Widget(searchBar->parent);
+            //setFlags_Widget(searchBar, hidden_WidgetFlag | disabled_WidgetFlag, iTrue);
+            //arrange_Widget(searchBar->parent);
+            showCollapsed_Widget(searchBar, iFalse);
             if (isFocused_Widget(findChild_Widget(searchBar, "find.input"))) {
                 setFocus_Widget(NULL);
             }
@@ -886,6 +892,7 @@ void updateMetrics_Root(iRoot *d) {
 
 void createUserInterface_Root(iRoot *d) {
     iWidget *root = d->widget = new_Widget();
+    root->rect.size = get_Window()->size;
     iAssert(root->root == d);
     setId_Widget(root, "root");
     /* Children of root cover the entire window. */
@@ -944,13 +951,14 @@ void createUserInterface_Root(iRoot *d) {
         setBackgroundColor_Widget(winBar, uiBackground_ColorId);
     }
 #endif
+    iWidget *navBar;
     /* Navigation bar. */ {
-        iWidget *navBar = new_Widget();
+        navBar = new_Widget();
         setId_Widget(navBar, "navbar");
         setFlags_Widget(navBar,
                         hittable_WidgetFlag | /* context menu */
                             arrangeHeight_WidgetFlag |
-                            resizeChildren_WidgetFlag |
+                            resizeWidthOfChildren_WidgetFlag |
                             arrangeHorizontal_WidgetFlag |
                             drawBackgroundToHorizontalSafeArea_WidgetFlag |
                             drawBackgroundToVerticalSafeArea_WidgetFlag,
@@ -958,7 +966,8 @@ void createUserInterface_Root(iRoot *d) {
         addChild_Widget(div, iClob(navBar));
         setBackgroundColor_Widget(navBar, uiBackground_ColorId);
         setCommandHandler_Widget(navBar, handleNavBarCommands_);
-        setId_Widget(addChildFlags_Widget(navBar, iClob(newIcon_LabelWidget(backArrow_Icon, 0, 0, "navigate.back")), collapse_WidgetFlag), "navbar.back");
+        iWidget *navBack;
+        setId_Widget(navBack = addChildFlags_Widget(navBar, iClob(newIcon_LabelWidget(backArrow_Icon, 0, 0, "navigate.back")), collapse_WidgetFlag), "navbar.back");
         setId_Widget(addChildFlags_Widget(navBar, iClob(newIcon_LabelWidget(forwardArrow_Icon, 0, 0, "navigate.forward")), collapse_WidgetFlag), "navbar.forward");
         /* Mobile devices have a button for easier access to the left sidebar. */
         if (deviceType_App() != desktop_AppDeviceType) {
@@ -999,7 +1008,7 @@ void createUserInterface_Root(iRoot *d) {
             setId_Widget(rightEmbed, "url.rightembed");
             addChildFlags_Widget(as_Widget(url),
                                  iClob(rightEmbed),
-                                 arrangeHorizontal_WidgetFlag | arrangeSize_WidgetFlag |
+                                 arrangeHorizontal_WidgetFlag | arrangeWidth_WidgetFlag |
                                      resizeHeightOfChildren_WidgetFlag |
                                      moveToParentRightEdge_WidgetFlag);
             /* Feeds refresh indicator is inside the input field. */ {
@@ -1132,8 +1141,8 @@ void createUserInterface_Root(iRoot *d) {
         iWidget *searchBar = new_Widget();
         setId_Widget(searchBar, "search");
         setFlags_Widget(searchBar,
-                        hidden_WidgetFlag | disabled_WidgetFlag | collapse_WidgetFlag |
-                            arrangeHeight_WidgetFlag | resizeChildren_WidgetFlag |
+                        hidden_WidgetFlag | disabledWhenHidden_WidgetFlag | collapse_WidgetFlag |
+                            arrangeHeight_WidgetFlag | resizeWidthOfChildren_WidgetFlag |
                             arrangeHorizontal_WidgetFlag,
                         iTrue);
         if (deviceType_App() == desktop_AppDeviceType) {
@@ -1270,6 +1279,7 @@ void createUserInterface_Root(iRoot *d) {
         addAction_Widget(root, SDLK_j, KMOD_PRIMARY, "splitmenu.open");
     }
     updateMetrics_Root(d);
+    updateNavBarSize_(navBar);
 }
 
 void showToolbars_Root(iRoot *d, iBool show) {
diff --git a/src/ui/util.c b/src/ui/util.c
index 0a0c37a9..7bc611e0 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -2061,8 +2061,8 @@ static iWidget *appendTwoColumnPage_(iWidget *tabs, const char *title, int short
                                      iWidget **values) {
     /* TODO: Use `makeTwoColumnWidget_()`, see above. */
     iWidget *page = new_Widget();
-    setFlags_Widget(page, arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag |
-                    resizeHeightOfChildren_WidgetFlag, iTrue);
+    setBackgroundColor_Widget(page, red_ColorId);
+    setFlags_Widget(page, arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag, iTrue);
     addChildFlags_Widget(page, iClob(new_Widget()), expand_WidgetFlag);
     setPadding_Widget(page, 0, gap_UI, 0, gap_UI);
     iWidget *columns = new_Widget();
diff --git a/src/ui/widget.c b/src/ui/widget.c
index e4d92b35..62112e86 100644
--- a/src/ui/widget.c
+++ b/src/ui/widget.c
@@ -232,11 +232,29 @@ void setRoot_Widget(iWidget *d, iRoot *root) {
     }
 }
 
+iLocalDef iBool isCollapsed_Widget_(const iWidget *d) {
+    return (d->flags & (hidden_WidgetFlag | collapse_WidgetFlag)) ==
+           (hidden_WidgetFlag | collapse_WidgetFlag);
+}
+
+iLocalDef iBool isArrangedPos_Widget_(const iWidget *d) {
+    return (d->flags & fixedPosition_WidgetFlag) == 0;
+}
+
+iLocalDef iBool isArrangedSize_Widget_(const iWidget *d) {
+    return !isCollapsed_Widget_(d) && isArrangedPos_Widget_(d) &&
+           !(d->flags & parentCannotResize_WidgetFlag);
+}
+
+iLocalDef iBool doesAffectSizing_Widget_(const iWidget *d) {
+    return !isCollapsed_Widget_(d) && isArrangedPos_Widget_(d);
+}
+
 static int numExpandingChildren_Widget_(const iWidget *d) {
     int count = 0;
     iConstForEach(ObjectList, i, d->children) {
         const iWidget *child = constAs_Widget(i.object);
-        if (flags_Widget(child) & expand_WidgetFlag) {
+        if (flags_Widget(child) & expand_WidgetFlag && doesAffectSizing_Widget_(child)) {
             count++;
         }
     }
@@ -253,7 +271,7 @@ static int widestChild_Widget_(const iWidget *d) {
 }
 
 static void arrange_Widget_(iWidget *);
-static const iBool tracing_ = iFalse;
+static const iBool tracing_ = 0;
 
 #define TRACE(d, ...)   if (tracing_) { printf_Widget_(d, __VA_ARGS__); }
 
@@ -288,7 +306,7 @@ static void setWidth_Widget_(iWidget *d, int width) {
     iAssert(width >= 0);
     TRACE(d, "attempt to set width to %d (current: %d, min width: %d)", width, d->rect.size.x, d->minSize.x);
     width = iMax(width, d->minSize.x);
-    if (~d->flags & fixedWidth_WidgetFlag || d->flags & collapse_WidgetFlag) {
+    if (~d->flags & fixedWidth_WidgetFlag) { //} || d->flags & collapse_WidgetFlag) {
         if (d->rect.size.x != width) {
             d->rect.size.x = width;
             TRACE(d, "width has changed to %d", width);
@@ -313,7 +331,7 @@ static void setHeight_Widget_(iWidget *d, int height) {
     iAssert(height >= 0);
     TRACE(d, "attempt to set height to %d (current: %d, min height: %d)", height, d->rect.size.y, d->minSize.y);
     height = iMax(height, d->minSize.y);
-    if (~d->flags & fixedHeight_WidgetFlag || d->flags & collapse_WidgetFlag) {
+    if (~d->flags & fixedHeight_WidgetFlag) { //} || d->flags & collapse_WidgetFlag) {
         if (d->rect.size.y != height) {
             d->rect.size.y = height;
             TRACE(d, "height has changed to %d", height);
@@ -327,11 +345,6 @@ static void setHeight_Widget_(iWidget *d, int height) {
     }
 }
 
-iLocalDef iBool isCollapsed_Widget_(const iWidget *d) {
-    return (d->flags & (hidden_WidgetFlag | collapse_WidgetFlag)) ==
-           (hidden_WidgetFlag | collapse_WidgetFlag);
-}
-
 iLocalDef iRect innerRect_Widget_(const iWidget *d) {
     return init_Rect(d->padding[0],
                      d->padding[1],
@@ -347,14 +360,15 @@ iRect innerBounds_Widget(const iWidget *d) {
     return ib;
 }
 
-iLocalDef iBool isArranged_Widget_(const iWidget *d) {
-    return !isCollapsed_Widget_(d) && ~d->flags & fixedPosition_WidgetFlag;
-}
+//iLocalDef iBool isArranged_Widget_(const iWidget *d) {
+//    return !isCollapsed_Widget_(d) && ~d->flags & fixedPosition_WidgetFlag;
+//}
+
 
 static size_t numArrangedChildren_Widget_(const iWidget *d) {
     size_t count = 0;
     iConstForEach(ObjectList, i, d->children) {
-        if (isArranged_Widget_(i.object)) {
+        if (isArrangedPos_Widget_(i.object)) {
             count++;
         }
     }
@@ -387,15 +401,20 @@ static void boundsOfChildren_Widget_(const iWidget *d, iRect *bounds_out) {
             *bounds_out = union_Rect(*bounds_out, childRect);
         }
     }
+#if !defined (NDEBUG)
+    if (tracing_) {
+        if (bounds_out->size.x && bounds_out->size.y == 0) {
+            printf("SUSPECT CHILD BOUNDS?\n");
+            puts  ("---------------------");
+            printTree_Widget(d);
+            puts  ("---------------------");
+        }
+    }
+#endif
 }
 
 static void arrange_Widget_(iWidget *d) {
     TRACE(d, "arranging...");
-    if (isCollapsed_Widget_(d)) {
-        TRACE(d, "collapsed => END");
-        setFlags_Widget(d, wasCollapsed_WidgetFlag, iTrue);
-        return;
-    }
     if (d->flags & moveToParentLeftEdge_WidgetFlag) {
         d->rect.pos.x = d->padding[0]; /* FIXME: Shouldn't this be d->parent->padding[0]? */
         TRACE(d, "move to parent left edge: %d", d->rect.pos.x);
@@ -439,57 +458,42 @@ static void arrange_Widget_(iWidget *d) {
     }
     const size_t childCount = numArrangedChildren_Widget_(d);
     TRACE(d, "%d arranged children", childCount);
+    const int expCount = numExpandingChildren_Widget_(d);
+    TRACE(d, "%d expanding children", expCount);
     /* Resize children to fill the parent widget. */
     if (d->flags & resizeChildren_WidgetFlag) {
         const iInt2 dirs = init_I2((d->flags & resizeWidthOfChildren_WidgetFlag) != 0,
                                    (d->flags & resizeHeightOfChildren_WidgetFlag) != 0);
-        TRACE(d, "resize children, x:%d y:%d", dirs.x, dirs.y);
-        /* Collapse hidden children. */
-        iBool collapseChanged = iFalse;
-        iForEach(ObjectList, c, d->children) {
-            iWidget *child = as_Widget(c.object);
-            if (!isCollapsed_Widget_(child) && child->flags & wasCollapsed_WidgetFlag) {
-                setFlags_Widget(child, wasCollapsed_WidgetFlag, iFalse);
-                TRACE(d, "child %p is uncollapsed", child);
-                /* Undo collapse and determine the normal size again. */
-                arrange_Widget_(d);
-                collapseChanged = iTrue;
-            }
-            else if (isCollapsed_Widget_(child) && ~child->flags & wasCollapsed_WidgetFlag) {
-                setFlags_Widget(child, wasCollapsed_WidgetFlag, iTrue);
-                collapseChanged = iTrue;
-                TRACE(d, "child %p flagged as collapsed", child);
-            }
-        }
-        if (collapseChanged) {
-            TRACE(d, "redoing arrangement due to changes in child collapse state");
-            arrange_Widget_(d); /* Redo with the new child sizes. */
-            return;
-        }
-        const int expCount = numExpandingChildren_Widget_(d);
-        TRACE(d, "%d expanding children", expCount);
-        /* Only resize the expanding children, not touching the others. */
+#if !defined (NDEBUG)
+        /* Check for conflicting flags. */
+        if (dirs.x) iAssert(~d->flags & arrangeWidth_WidgetFlag);
+        if (dirs.y) iAssert(~d->flags & arrangeHeight_WidgetFlag);
+#endif
+        TRACE(d, "resize children, x:%d y:%d (own size: %dx%d)", dirs.x, dirs.y,
+              d->rect.size.x, d->rect.size.y);
         if (expCount > 0) {
+            /* There are expanding children, so all non-expanding children will retain their
+               current size. */
             iInt2 avail = innerRect_Widget_(d).size;
             TRACE(d, "inner size: %dx%d", avail.x, avail.y);
             iConstForEach(ObjectList, i, d->children) {
                 const iWidget *child = constAs_Widget(i.object);
-                if (!isArranged_Widget_(child)) {
-                    continue;
-                }
-                if (~child->flags & expand_WidgetFlag) {
-                    subv_I2(&avail, child->rect.size);
+                if (doesAffectSizing_Widget_(child)) {
+                    if (~child->flags & expand_WidgetFlag) {
+                        subv_I2(&avail, child->rect.size);
+                    }
                 }
             }
             avail = divi_I2(max_I2(zero_I2(), avail), expCount);
-            TRACE(d, "changing child sizes (expand mode)...");
+            TRACE(d, "changing child sizes...");
             iForEach(ObjectList, j, d->children) {
                 iWidget *child = as_Widget(j.object);
-                if (!isArranged_Widget_(child)) {
-                    TRACE(d, "child %p is not arranged", child);
+                if (!isArrangedSize_Widget_(child)) {
+                    TRACE(d, "child %p size is not arranged", child);
                     continue;
                 }
-                if (child->flags & expand_WidgetFlag) {
+                if (~child->flags & expand_WidgetFlag) {
+#if 0
                     if (d->flags & arrangeHorizontal_WidgetFlag) {
                         if (dirs.x) setWidth_Widget_(child, avail.x);
                         if (dirs.y) setHeight_Widget_(child, height_Rect(innerRect_Widget_(d)));
@@ -500,6 +504,7 @@ static void arrange_Widget_(iWidget *d) {
                     }
                 }
                 else {
+#endif
                     /* Fill the off axis, though. */
                     if (d->flags & arrangeHorizontal_WidgetFlag) {
                         if (dirs.y) setHeight_Widget_(child, height_Rect(innerRect_Widget_(d)));
@@ -509,7 +514,7 @@ static void arrange_Widget_(iWidget *d) {
                     }
                 }
             }
-            TRACE(d, "...done changing child sizes (expand mode)");
+            TRACE(d, "...done changing child sizes");
         }
         else {
             /* Evenly size all children. */
@@ -526,7 +531,7 @@ static void arrange_Widget_(iWidget *d) {
             TRACE(d, "begin changing child sizes (EVEN mode)...");
             iForEach(ObjectList, i, d->children) {
                 iWidget *child = as_Widget(i.object);
-                if (isArranged_Widget_(child) && ~child->flags & parentCannotResize_WidgetFlag) {
+                if (isArrangedSize_Widget_(child)) {
                     if (dirs.x) {
                         setWidth_Widget_(child, child->flags & unpadded_WidgetFlag ? unpaddedChildSize.x : childSize.x);
                     }
@@ -535,19 +540,55 @@ static void arrange_Widget_(iWidget *d) {
                     }
                 }
                 else {
-                    TRACE(d, "child %p cannot be resized (parentCannotResize: %d)", child,
+                    TRACE(d, "child %p cannot be resized (collapsed: %d, arrangedPos: %d, parentCannotResize: %d)", child,
+                          isCollapsed_Widget_(child),
+                          isArrangedPos_Widget_(child),
                           (child->flags & parentCannotResize_WidgetFlag) != 0);
                 }
             }
             TRACE(d, "...done changing child sizes (EVEN mode)");
         }
     }
+    /* Resize the expanding children to fill the remaining available space. */
+    if (expCount > 0 && (d->flags & (arrangeHorizontal_WidgetFlag | arrangeVertical_WidgetFlag))) {
+        TRACE(d, "%d expanding children, resizing them %s...", expCount,
+              d->flags & arrangeHorizontal_WidgetFlag ? "horizontally" : "vertically");
+        const iRect innerRect = innerRect_Widget_(d);
+        iInt2 avail = innerRect.size;
+        iConstForEach(ObjectList, i, d->children) {
+            const iWidget *child = constAs_Widget(i.object);
+            if (doesAffectSizing_Widget_(child)) {
+                if (~child->flags & expand_WidgetFlag) {
+                    subv_I2(&avail, child->rect.size);
+                }
+            }
+        }
+        avail = divi_I2(max_I2(zero_I2(), avail), expCount);
+        TRACE(d, "available for expansion (per child): %d\n", d->flags & arrangeHorizontal_WidgetFlag ? avail.x : avail.y);
+        iForEach(ObjectList, j, d->children) {
+            iWidget *child = as_Widget(j.object);
+            if (!isArrangedSize_Widget_(child)) {
+                TRACE(d, "child %p size is not arranged", child);
+                continue;
+            }
+            if (child->flags & expand_WidgetFlag) {
+                if (d->flags & arrangeHorizontal_WidgetFlag) {
+                    setWidth_Widget_(child, avail.x);
+                    setHeight_Widget_(child, height_Rect(innerRect));
+                }
+                else if (d->flags & arrangeVertical_WidgetFlag) {
+                    setWidth_Widget_(child, width_Rect(innerRect));
+                    setHeight_Widget_(child, avail.y);
+                }
+            }
+        }
+    }
     if (d->flags & resizeChildrenToWidestChild_WidgetFlag) {
         const int widest = widestChild_Widget_(d);
         TRACE(d, "resizing children to widest child (%d)...", widest);
         iForEach(ObjectList, i, d->children) {
             iWidget *child = as_Widget(i.object);
-            if (isArranged_Widget_(child) && ~child->flags & parentCannotResize_WidgetFlag) {
+            if (isArrangedSize_Widget_(child)) {
                 setWidth_Widget_(child, widest);
             }
             else {
@@ -564,7 +605,7 @@ static void arrange_Widget_(iWidget *d) {
     iForEach(ObjectList, i, d->children) {
         iWidget *child = as_Widget(i.object);
         arrange_Widget_(child);
-        if (!isArranged_Widget_(child)) {
+        if (isCollapsed_Widget_(child) || !isArrangedPos_Widget_(child)) {
             TRACE(d, "child %p arranging prohibited", child);
             continue;
         }
@@ -648,6 +689,7 @@ static void arrange_Widget_(iWidget *d) {
     TRACE(d, "END");
 }
 
+#if 0
 void resetSize_Widget(iWidget *d) {
     if (~d->flags & fixedWidth_WidgetFlag) {
         d->rect.size.x = d->minSize.x;
@@ -657,11 +699,12 @@ void resetSize_Widget(iWidget *d) {
     }
     iForEach(ObjectList, i, children_Widget(d)) {
         iWidget *child = as_Widget(i.object);
-        if (isArranged_Widget_(child)) {
+        if (isArrangedSize_Widget_(child)) {
             resetSize_Widget(child);
         }
     }
 }
+#endif
 
 void arrange_Widget(iWidget *d) {
     //resetSize_Widget_(d); /* back to initial default sizes */
diff --git a/src/ui/widget.h b/src/ui/widget.h
index c3c9609e..36797210 100644
--- a/src/ui/widget.h
+++ b/src/ui/widget.h
@@ -87,7 +87,8 @@ enum iWidgetFlag {
 };
 
 /* 64-bit extended flags */
-#define wasCollapsed_WidgetFlag             iBit64(32)
+//#define wasCollapsed_WidgetFlag             iBit64(32)
+#define disabledWhenHidden_WidgetFlag       iBit64(32)
 #define centerHorizontal_WidgetFlag         iBit64(33)
 #define moveToParentLeftEdge_WidgetFlag     iBit64(34)
 #define moveToParentRightEdge_WidgetFlag    iBit64(35)
@@ -116,7 +117,6 @@ enum iWidgetFlag {
 #define parentCannotResizeHeight_WidgetFlag iBit64(58)
 #define ignoreForParentWidth_WidgetFlag     iBit64(59)
 #define noFadeBackground_WidgetFlag         iBit64(60)
-#define disabledWhenHidden_WidgetFlag       iBit64(61)
 
 enum iWidgetAddPos {
     back_WidgetAddPos,
diff --git a/src/ui/window.c b/src/ui/window.c
index 9ac9b918..704e6f2a 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -471,6 +471,7 @@ void init_Window(iWindow *d, iRect rect) {
     d->frameTime = SDL_GetTicks();
     d->loadAnimTimer = 0;
     init_Text(d->render);
+    SDL_GetRendererOutputSize(d->render, &d->size.x, &d->size.y);
     setupUserInterface_Window(d);
     postCommand_App("~bindings.changed"); /* update from bindings */
     updateSize_Window_(d, iFalse);
@@ -1175,6 +1176,7 @@ void setSplitMode_Window(iWindow *d, int splitMode) {
             iAssert(d->roots[1] == NULL);
             d->roots[1] = new_Root();
             setCurrent_Root(d->roots[1]);
+            d->keyRoot = d->roots[1];
             createUserInterface_Root(d->roots[1]);
             /* If the old root has multiple tabs, move the current one to the new split. */ {
                 iWidget *docTabs0 = findChild_Widget(d->roots[0]->widget, "doctabs");
@@ -1186,7 +1188,8 @@ void setSplitMode_Window(iWindow *d, int splitMode) {
                     iRelease(removeTabPage_Widget(docTabs1, 0)); /* delete the default tab */
                     setRoot_Widget(as_Widget(moved), d->roots[1]);
                     prependTabPage_Widget(docTabs1, iClob(moved), "", 0, 0);
-                    showTabPage_Widget(docTabs1, as_Widget(moved));
+                    //showTabPage_Widget(docTabs1, as_Widget(moved));
+                    postCommandf_App("tabs.switch page:%p", moved);
                 }
                 else {
                     postCommand_Root(d->roots[1], "navigate.home");