Refactor: Added a proper Root object

`Root` encapsulates the root widget and the associated UI state.

10 files changed, 129 insertions, 127 deletions

diff --git a/src/app.c b/src/app.c
index c4511dc7..cefb707d 100644
--- a/src/app.c
+++ b/src/app.c
@@ -1046,7 +1046,7 @@ void processEvents_App(enum iAppEventMode eventMode) {
                     handleCommand_MacOS(command_UserEvent(&ev));
 #endif
                     if (isMetricsChange_UserEvent(&ev)) {
-                        arrange_Widget(d->window->root);
+                        arrange_Widget(d->window->root.widget);
                     }
                     if (!wasUsed) {
                         /* No widget handled the command, so we'll do it. */
@@ -1131,7 +1131,7 @@ static int run_App_(iApp *d) {
 
 void refresh_App(void) {
     iApp *d = &app_;
-    destroyPending_RootData(data_Root());
+    destroyPending_Root(&d->window->root);
 #if defined (LAGRANGE_ENABLE_IDLE_SLEEP)
     if (d->warmupFrames == 0 && d->isIdling) {
         return;
@@ -1262,7 +1262,7 @@ void postCommandf_App(const char *command, ...) {
 
 iAny *findWidget_App(const char *id) {
     if (!*id) return NULL;
-    return findChild_Widget(app_.window->root, id);
+    return findChild_Widget(app_.window->root.widget, id);
 }
 
 void addTicker_App(iTickerFunc ticker, iAny *context) {
@@ -2120,7 +2120,7 @@ iBool handleCommand_App(const char *cmd) {
     else if (equal_Command(cmd, "ident.import")) {
         iCertImportWidget *imp = new_CertImportWidget();
         setPageContent_CertImportWidget(imp, sourceContent_DocumentWidget(document_App()));
-        addChild_Widget(d->window->root, iClob(imp));
+        addChild_Widget(d->window->root.widget, iClob(imp));
         finalizeSheet_Widget(as_Widget(imp));
         postRefresh_App();
         return iTrue;
diff --git a/src/ui/paint.c b/src/ui/paint.c
index 857bf20c..02914489 100644
--- a/src/ui/paint.c
+++ b/src/ui/paint.c
@@ -87,8 +87,8 @@ void unsetClip_Paint(iPaint *d) {
 void drawRect_Paint(const iPaint *d, iRect rect, int color) {
     iInt2 br = bottomRight_Rect(rect);
     /* Keep the right/bottom edge visible in the window. */
-    if (br.x == d->dst->root->rect.size.x) br.x--;
-    if (br.y == d->dst->root->rect.size.y) br.y--;
+    if (br.x == d->dst->root.widget->rect.size.x) br.x--;
+    if (br.y == d->dst->root.widget->rect.size.y) br.y--;
     const SDL_Point edges[] = {
         { left_Rect(rect),  top_Rect(rect) },
         { br.x, top_Rect(rect) },
diff --git a/src/ui/root.c b/src/ui/root.c
index f6b93abd..1fa36851 100644
--- a/src/ui/root.c
+++ b/src/ui/root.c
@@ -234,23 +234,27 @@ static const char *stopSeqCStr_[] = {
 static const int loadAnimIntervalMs_ = 133;
 static int       loadAnimIndex_      = 0;
 
-static iWidget *    activeRoot_     = NULL;
-static iRootData *  activeRootData_ = NULL;
+static iRoot *   activeRoot_     = NULL;
 
-void setCurrent_Root(iWidget *root, iRootData *rootData) {
-    activeRoot_ = root;
-    activeRootData_ = rootData;
+iDefineTypeConstruction(Root)
+    
+void init_Root(iRoot *d) {
+    iZap(*d);    
 }
 
-iWidget *get_Root(void) {
-    return activeRoot_;
+void deinit_Root(iRoot *d) {
+    iReleasePtr(&d->widget);    
+}
+
+void setCurrent_Root(iRoot *root) {
+    activeRoot_ = root;
 }
 
-iRootData *data_Root(void) {
-    return activeRootData_;
+iRoot *get_Root(void) {
+    return activeRoot_;
 }
 
-void destroyPending_RootData(iRootData *d) {
+void destroyPending_Root(iRoot *d) {
     iForEach(PtrSet, i, d->pendingDestruction) {
         iWidget *widget = *i.value;
         if (!isFinished_Anim(&widget->visualOffset)) {
@@ -265,12 +269,11 @@ void destroyPending_RootData(iRootData *d) {
     }
 }
 
-iPtrArray *onTop_RootData(void) {
-    iAssert(activeRootData_);
-    if (!activeRootData_->onTop) {
-        activeRootData_->onTop = new_PtrArray();
+iPtrArray *onTop_Root(iRoot *d) {
+    if (!d->onTop) {
+        d->onTop = new_PtrArray();
     }
-    return activeRootData_->onTop;
+    return d->onTop;
 }
 
 static iBool handleRootCommands_(iWidget *root, const char *cmd) {
@@ -423,7 +426,7 @@ static uint32_t updateReloadAnimation_Window_(uint32_t interval, void *window) {
 
 static void setReloadLabel_Window_(iWindow *d, iBool animating) {
     const iBool isMobile = deviceType_App() != desktop_AppDeviceType;
-    iLabelWidget *label = findChild_Widget(d->root, "reload");
+    iLabelWidget *label = findChild_Widget(d->root.widget, "reload");
     updateTextCStr_LabelWidget(label, animating ? loadAnimationCStr_() :
                                                 (isMobile ? pageMenuCStr_ : reloadCStr_));
     if (isMobile) {
@@ -444,13 +447,13 @@ static void checkLoadAnimation_Window_(iWindow *d) {
     setReloadLabel_Window_(d, isOngoing);
 }
 
-void updatePadding_Root(iWidget *d) {
+void updatePadding_Root(iRoot *d) {
 #if defined (iPlatformAppleMobile)
-    iWidget *toolBar = findChild_Widget(d, "toolbar");
+    iWidget *toolBar = findChild_Widget(d->widget, "toolbar");
     float left, top, right, bottom;
     safeAreaInsets_iOS(&left, &top, &right, &bottom);
     /* Respect the safe area insets. */ {
-        setPadding_Widget(findChild_Widget(d, "navdiv"), left, top, right, 0);
+        setPadding_Widget(findChild_Widget(d->widget, "navdiv"), left, top, right, 0);
         if (toolBar) {
             setPadding_Widget(toolBar, left, 0, right, bottom);
         }
@@ -458,8 +461,8 @@ void updatePadding_Root(iWidget *d) {
     if (toolBar) {
         /* TODO: get this from toolBar height, but it's buggy for some reason */
         const int sidebarBottomPad = isPortrait_App() ? 11 * gap_UI + bottom : 0;
-        setPadding_Widget(findChild_Widget(d, "sidebar"), 0, 0, 0, sidebarBottomPad);
-        setPadding_Widget(findChild_Widget(d, "sidebar2"), 0, 0, 0, sidebarBottomPad);
+        setPadding_Widget(findChild_Widget(d->widget, "sidebar"), 0, 0, 0, sidebarBottomPad);
+        setPadding_Widget(findChild_Widget(d->widget, "sidebar2"), 0, 0, 0, sidebarBottomPad);
         /* TODO: There seems to be unrelated layout glitch in the sidebar where its children
            are not arranged correctly until it's hidden and reshown. */
     }
@@ -469,10 +472,10 @@ void updatePadding_Root(iWidget *d) {
 #endif
 }
 
-void dismissPortraitPhoneSidebars_Root(iWidget *root) {
+void dismissPortraitPhoneSidebars_Root(iRoot *d) {
     if (deviceType_App() == phone_AppDeviceType && isPortrait_App()) {
-        iWidget *sidebar = findChild_Widget(root, "sidebar");
-        iWidget *sidebar2 = findChild_Widget(root, "sidebar2");
+        iWidget *sidebar = findChild_Widget(d->widget, "sidebar");
+        iWidget *sidebar2 = findChild_Widget(d->widget, "sidebar2");
         if (isVisible_Widget(sidebar)) {
             postCommand_App("sidebar.toggle");
             setVisualOffset_Widget(sidebar, height_Widget(sidebar), 250, easeIn_AnimFlag);
@@ -564,7 +567,7 @@ static iBool handleNavBarCommands_(iWidget *navBar, const char *cmd) {
                     updateSize_LabelWidget(btn);
                 }
             }
-            arrange_Widget(get_Window()->root);
+            arrange_Widget(get_Window()->root.widget);
         }
         /* Resize the URL input field. */ {
             iWidget *urlBar = findChild_Widget(navBar, "url");
@@ -716,7 +719,7 @@ static iBool handleSearchBarCommands_(iWidget *searchBar, const char *cmd) {
         if (pointer_Command(cmd) == findChild_Widget(searchBar, "find.input")) {
             if (!isVisible_Widget(searchBar)) {
                 setFlags_Widget(searchBar, hidden_WidgetFlag | disabled_WidgetFlag, iFalse);
-                arrange_Widget(get_Window()->root);
+                arrange_Widget(get_Window()->root.widget);
                 postRefresh_App();
             }
         }
@@ -824,9 +827,9 @@ static int appIconSize_(void) {
     return lineHeight_Text(uiContent_FontId);
 }
 
-void updateMetrics_Root(iWidget *d) {
+void updateMetrics_Root(iRoot *d) {
     /* Custom frame. */
-    iWidget *winBar = findChild_Widget(d, "winbar");
+    iWidget *winBar = findChild_Widget(d->widget, "winbar");
     if (winBar) {
         iWidget *appIcon  = findChild_Widget(winBar, "winbar.icon");
         iWidget *appTitle = findChild_Widget(winBar, "winbar.title");
@@ -839,9 +842,9 @@ void updateMetrics_Root(iWidget *d) {
         setFixedSize_Widget(appClose, appMin->rect.size);
         setFixedSize_Widget(appIcon, init_I2(appIconSize_(), appMin->rect.size.y));
     }
-    iWidget *navBar     = findChild_Widget(d, "navbar");
+    iWidget *navBar     = findChild_Widget(d->widget, "navbar");
     iWidget *lock       = findChild_Widget(navBar, "navbar.lock");
-    iWidget *url        = findChild_Widget(d, "url");
+    iWidget *url        = findChild_Widget(d->widget, "url");
     iWidget *rightEmbed = findChild_Widget(navBar, "url.rightembed");
     iWidget *embedPad   = findChild_Widget(navBar, "url.embedpad");
     setPadding_Widget(as_Widget(url), 0, gap_UI, 0, gap_UI);
@@ -852,12 +855,12 @@ void updateMetrics_Root(iWidget *d) {
                                   width_Widget(lock) * 0.75);
     rightEmbed->rect.pos.y = gap_UI;
     updatePadding_Root(d);
-    arrange_Widget(d);
+    arrange_Widget(d->widget);
     postRefresh_App();
 }
 
-iWidget *createUserInterface_Root(void) {
-    iWidget *root = new_Widget();
+void createUserInterface_Root(iRoot *d) {
+    iWidget *root = d->widget = new_Widget();
     setId_Widget(root, "root");
     /* Children of root cover the entire window. */
     setFlags_Widget(
@@ -1180,7 +1183,7 @@ iWidget *createUserInterface_Root(void) {
         setId_Widget(menu, "toolbar.menu"); /* view menu */
         }
 #endif
-    updatePadding_Root(root);
+    updatePadding_Root(d);
     /* Global context menus. */ {
         iWidget *tabsMenu = makeMenu_Widget(
             root,
@@ -1226,14 +1229,13 @@ iWidget *createUserInterface_Root(void) {
         addAction_Widget(root, '4', rightSidebar_KeyModifier, "sidebar2.mode arg:3 toggle:1");
         addAction_Widget(root, '5', rightSidebar_KeyModifier, "sidebar2.mode arg:4 toggle:1");
     }
-    updateMetrics_Root(root);
-    return root;
+    updateMetrics_Root(d);
 }
 
-void showToolbars_Root(iWidget *root, iBool show) {
+void showToolbars_Root(iRoot *d, iBool show) {
     /* The toolbar is only used on phone portrait layout. */
     if (isLandscape_App()) return;
-    iWidget *toolBar = findChild_Widget(root, "toolbar");
+    iWidget *toolBar = findChild_Widget(d->widget, "toolbar");
     if (!toolBar) return;
     const int height = rootSize_Window(get_Window()).y - top_Rect(boundsWithoutVisualOffset_Widget(toolBar));
     if (show && !isVisible_Widget(toolBar)) {
diff --git a/src/ui/root.h b/src/ui/root.h
index fcb5b1b0..4b14b942 100644
--- a/src/ui/root.h
+++ b/src/ui/root.h
@@ -3,10 +3,10 @@
 #include "widget.h"
 #include <the_Foundation/ptrset.h>
 
-iDeclareType(RootData)
+iDeclareType(Root)
     
-/* TODO: Rename to Root, include `iWidget *root` as well. */
-struct Impl_RootData {
+struct Impl_Root {
+    iWidget *  widget;
     iWidget *  hover;
     iWidget *  mouseGrab;
     iWidget *  focus;
@@ -14,18 +14,19 @@ struct Impl_RootData {
     iPtrSet *  pendingDestruction;
 };
 
+iDeclareTypeConstruction(Root)
+
 /*----------------------------------------------------------------------------------------------*/
 
-iWidget *   createUserInterface_Root            (void);
+void        createUserInterface_Root            (iRoot *);
 
-void        setCurrent_Root                     (iWidget *root, iRootData *rootData);
-iWidget *   get_Root                            (void);
-iRootData * data_Root                           (void);
+void        setCurrent_Root                     (iRoot *);
+iRoot *     get_Root                            (void);
 
-iPtrArray * onTop_RootData                      (void);
-void        destroyPending_RootData             (iRootData *);
+iPtrArray * onTop_Root                          (iRoot *);
+void        destroyPending_Root                 (iRoot *);
     
-void        updateMetrics_Root                  (iWidget *);
-void        updatePadding_Root                  (iWidget *); /* TODO: is part of metrics? */
-void        dismissPortraitPhoneSidebars_Root   (iWidget *);
-void        showToolbars_Root                   (iWidget *, iBool show);
+void        updateMetrics_Root                  (iRoot *);
+void        updatePadding_Root                  (iRoot *); /* TODO: is part of metrics? */
+void        dismissPortraitPhoneSidebars_Root   (iRoot *);
+void        showToolbars_Root                   (iRoot *, iBool show);
diff --git a/src/ui/sidebarwidget.c b/src/ui/sidebarwidget.c
index 683f6436..8d83eed6 100644
--- a/src/ui/sidebarwidget.c
+++ b/src/ui/sidebarwidget.c
@@ -1170,7 +1170,7 @@ static iBool processEvent_SidebarWidget_(iSidebarWidget *d, const SDL_Event *ev)
         else if (isCommand_Widget(w, ev, "ident.edit")) {
             const iGmIdentity *ident = menuIdentity_SidebarWidget_(d);
             if (ident) {
-                makeValueInput_Widget(get_Window()->root,
+                makeValueInput_Widget(get_Window()->root.widget,
                                       &ident->notes,
                                       uiHeading_ColorEscape "${heading.ident.notes}",
                                       format_CStr(cstr_Lang("dlg.ident.notes"), cstr_String(name_GmIdentity(ident))),
diff --git a/src/ui/touch.c b/src/ui/touch.c
index 22f22f9b..75bbf765 100644
--- a/src/ui/touch.c
+++ b/src/ui/touch.c
@@ -161,7 +161,7 @@ static iBool clearWidgetMomentum_TouchState_(iTouchState *d, iWidget *widget) {
 
 static void dispatchMotion_Touch_(iFloat3 pos, int buttonState) {
     touchState_()->currentTouchPos = initF3_I2(pos);
-    dispatchEvent_Widget(get_Window()->root, (SDL_Event *) &(SDL_MouseMotionEvent){
+    dispatchEvent_Widget(get_Window()->root.widget, (SDL_Event *) &(SDL_MouseMotionEvent){
         .type = SDL_MOUSEMOTION,
         .timestamp = SDL_GetTicks(),
         .which = SDL_TOUCH_MOUSEID,
@@ -185,12 +185,12 @@ static iBool dispatchClick_Touch_(const iTouch *d, int button) {
         .x = x_F3(tapPos),
         .y = y_F3(tapPos)
     };
-    iBool wasUsed = dispatchEvent_Widget(window->root, (SDL_Event *) &btn);
+    iBool wasUsed = dispatchEvent_Widget(window->root.widget, (SDL_Event *) &btn);
     /* Immediately released, too. */
     btn.type = SDL_MOUSEBUTTONUP;
     btn.state = SDL_RELEASED;
     btn.timestamp = SDL_GetTicks();
-    dispatchEvent_Widget(window->root, (SDL_Event *) &btn);
+    dispatchEvent_Widget(window->root.widget, (SDL_Event *) &btn);
     if (!wasUsed && button == SDL_BUTTON_RIGHT) {
         postContextClick_Window(window, &btn);
     }
@@ -199,7 +199,7 @@ static iBool dispatchClick_Touch_(const iTouch *d, int button) {
 
 static void dispatchButtonDown_Touch_(iFloat3 pos) {
     touchState_()->currentTouchPos = initF3_I2(pos);
-    dispatchEvent_Widget(get_Window()->root, (SDL_Event *) &(SDL_MouseButtonEvent){
+    dispatchEvent_Widget(get_Window()->root.widget, (SDL_Event *) &(SDL_MouseButtonEvent){
         .type = SDL_MOUSEBUTTONDOWN,
         .timestamp = SDL_GetTicks(),
         .clicks = 1,
@@ -213,7 +213,7 @@ static void dispatchButtonDown_Touch_(iFloat3 pos) {
 
 static void dispatchButtonUp_Touch_(iFloat3 pos) {
     touchState_()->currentTouchPos = initF3_I2(pos);
-    dispatchEvent_Widget(get_Window()->root, (SDL_Event *) &(SDL_MouseButtonEvent){
+    dispatchEvent_Widget(get_Window()->root.widget, (SDL_Event *) &(SDL_MouseButtonEvent){
         .type = SDL_MOUSEBUTTONUP,
         .timestamp = SDL_GetTicks(),
         .clicks = 1,
@@ -458,7 +458,7 @@ iBool processEvent_Touch(const SDL_Event *ev) {
         else if (x > rootSize.x - edgeWidth) {
             edge = right_TouchEdge;
         }
-        iWidget *aff = hitChild_Widget(window->root, init_I2(iRound(x), iRound(y_F3(pos))));
+        iWidget *aff = hitChild_Widget(window->root.widget, init_I2(iRound(x), iRound(y_F3(pos))));
         if (edge == left_TouchEdge) {
             dragging = findSlidePanel_Widget_(aff);
             if (dragging) {
diff --git a/src/ui/util.c b/src/ui/util.c
index b80f7650..6b9a43d9 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -635,7 +635,7 @@ static iBool menuHandler_(iWidget *menu, const char *cmd) {
         }
         if ((equal_Command(cmd, "mouse.clicked") || equal_Command(cmd, "mouse.missed")) &&
             arg_Command(cmd)) {
-            if (hitChild_Widget(get_Window()->root, coord_Command(cmd)) == parentMenuButton_(menu)) {
+            if (hitChild_Widget(get_Window()->root.widget, coord_Command(cmd)) == parentMenuButton_(menu)) {
                 return iFalse;
             }
             /* Dismiss open menus when clicking outside them. */
@@ -1366,7 +1366,7 @@ void finalizeSheet_Widget(iWidget *sheet) {
        easier to create phone versions of each dialog, but at least this works with any
        future changes to the UI (..."works"). At least this way it is possible to enforce
        a consistent styling. */
-    if (deviceType_App() == phone_AppDeviceType && parent_Widget(sheet) == get_Window()->root) {
+    if (deviceType_App() == phone_AppDeviceType && parent_Widget(sheet) == get_Window()->root.widget) {
         if (~flags_Widget(sheet) & keepOnTop_WidgetFlag) {
             /* Already finalized. */
             arrange_Widget(sheet);
@@ -1573,7 +1573,7 @@ void finalizeSheet_Widget(iWidget *sheet) {
             destroy_Widget(pageContent);
             setFlags_Widget(owner, drawBackgroundToBottom_WidgetFlag, iTrue);
         }
-        destroyPending_RootData(data_Root());
+        destroyPending_Root(get_Root());
         /* Additional elements for preferences. */
         if (isPrefs) {
             addChild_Widget(topPanel, iClob(makePadding_Widget(lineHeight_Text(defaultBig_FontId))));
@@ -1966,7 +1966,7 @@ iWidget *makeQuestion_Widget(const char *title, const char *msg,
     }
     addChild_Widget(dlg, iClob(makePadding_Widget(gap_UI)));
     addChild_Widget(dlg, iClob(makeDialogButtons_Widget(items, numItems)));
-    addChild_Widget(get_Window()->root, iClob(dlg));
+    addChild_Widget(get_Window()->root.widget, iClob(dlg));
     arrange_Widget(dlg); /* BUG: This extra arrange shouldn't be needed but the dialog won't
                             be arranged correctly unless it's here. */
     finalizeSheet_Widget(dlg);
@@ -2412,7 +2412,7 @@ iWidget *makePreferences_Widget(void) {
     addChild_Widget(dlg,
                     iClob(makeDialogButtons_Widget(
                         (iMenuItem[]){ { "${dismiss}", SDLK_ESCAPE, 0, "prefs.dismiss" } }, 1)));
-    addChild_Widget(get_Window()->root, iClob(dlg));
+    addChild_Widget(get_Window()->root.widget, iClob(dlg));
     finalizeSheet_Widget(dlg);
     //printTree_Widget(dlg);
     return dlg;
@@ -2445,7 +2445,7 @@ iWidget *makeBookmarkEditor_Widget(void) {
                                                   KMOD_PRIMARY,
                                                   "bmed.accept" } },
                                  2)));
-    addChild_Widget(get_Window()->root, iClob(dlg));
+    addChild_Widget(get_Window()->root.widget, iClob(dlg));
     finalizeSheet_Widget(dlg);
     return dlg;
 }
@@ -2578,7 +2578,7 @@ iWidget *makeFeedSettings_Widget(uint32_t bookmarkId) {
     setId_Widget(child_Widget(buttons, childCount_Widget(buttons) - 1), "feedcfg.save");
     arrange_Widget(dlg);
     as_Widget(input)->rect.size.x = 100 * gap_UI - headings->rect.size.x;
-    addChild_Widget(get_Window()->root, iClob(dlg));
+    addChild_Widget(get_Window()->root.widget, iClob(dlg));
     finalizeSheet_Widget(dlg);
     /* Initialize. */ {
         const iBookmark *bm  = bookmarkId ? get_Bookmarks(bookmarks_App(), bookmarkId) : NULL;
@@ -2654,7 +2654,7 @@ iWidget *makeIdentityCreation_Widget(void) {
                                          KMOD_PRIMARY,
                                          "ident.accept" } },
                         2)));
-    addChild_Widget(get_Window()->root, iClob(dlg));
+    addChild_Widget(get_Window()->root.widget, iClob(dlg));
     finalizeSheet_Widget(dlg);
     return dlg;
 }
diff --git a/src/ui/widget.c b/src/ui/widget.c
index b3f7b27f..47522dbe 100644
--- a/src/ui/widget.c
+++ b/src/ui/widget.c
@@ -81,7 +81,7 @@ void deinit_Widget(iWidget *d) {
 //#endif
     deinit_String(&d->id);
     if (d->flags & keepOnTop_WidgetFlag) {
-        removeAll_PtrArray(onTop_RootData(), d);
+        removeAll_PtrArray(onTop_Root(get_Root()), d);
     }
     if (d->flags & visualOffset_WidgetFlag) {
         removeTicker_App(visualOffsetAnimation_Widget_, d);
@@ -95,10 +95,10 @@ static void aboutToBeDestroyed_Widget_(iWidget *d) {
         return;
     }
     if (flags_Widget(d) & keepOnTop_WidgetFlag) {
-        removeOne_PtrArray(onTop_RootData(), d);
+        removeOne_PtrArray(onTop_Root(get_Root()), d);
     }
     if (isHover_Widget(d)) {
-        data_Root()->hover = NULL;
+        get_Root()->hover = NULL;
     }
     iForEach(ObjectList, i, d->children) {
         aboutToBeDestroyed_Widget_(as_Widget(i.object));
@@ -111,10 +111,11 @@ void destroy_Widget(iWidget *d) {
             postRefresh_App();
         }
         aboutToBeDestroyed_Widget_(d);
-        if (!data_Root()->pendingDestruction) {
-            data_Root()->pendingDestruction = new_PtrSet();
+        iRoot *root = get_Root();
+        if (!root->pendingDestruction) {
+            root->pendingDestruction = new_PtrSet();
         }
-        insert_PtrSet(data_Root()->pendingDestruction, d);
+        insert_PtrSet(root->pendingDestruction, d);
     }
 }
 
@@ -138,7 +139,7 @@ void setFlags_Widget(iWidget *d, int64_t flags, iBool set) {
         }
         iChangeFlags(d->flags, flags, set);
         if (flags & keepOnTop_WidgetFlag) {
-            iPtrArray *onTop = onTop_RootData();
+            iPtrArray *onTop = onTop_Root(get_Root());
             if (set) {
                 iAssert(indexOf_PtrArray(onTop, d) == iInvalidPos);
                 pushBack_PtrArray(onTop, d);
@@ -186,7 +187,7 @@ void showCollapsed_Widget(iWidget *d, iBool show) {
     if ((isVisible && !show) || (!isVisible && show)) {
         setFlags_Widget(d, hidden_WidgetFlag, !show);
         /* The entire UI may be affected, if parents are resized due to the (un)collapsing. */
-        arrange_Widget(get_Window()->root);
+        arrange_Widget(get_Window()->root.widget);
         postRefresh_App();
     }
 }
@@ -733,7 +734,7 @@ static iBool filterEvent_Widget_(const iWidget *d, const SDL_Event *ev) {
 }
 
 void unhover_Widget(void) {
-    data_Root()->hover = NULL;
+    get_Root()->hover = NULL;
 }
 
 iBool dispatchEvent_Widget(iWidget *d, const SDL_Event *ev) {
@@ -743,14 +744,14 @@ iBool dispatchEvent_Widget(iWidget *d, const SDL_Event *ev) {
             /* Hover widget may change. */
             setHover_Widget(NULL);
         }
-        if (data_Root()->focus && isKeyboardEvent_(ev)) {
+        if (get_Root()->focus && isKeyboardEvent_(ev)) {
             /* Root dispatches keyboard events directly to the focused widget. */
-            if (dispatchEvent_Widget(data_Root()->focus, ev)) {
+            if (dispatchEvent_Widget(get_Root()->focus, ev)) {
                 return iTrue;
             }
         }
         /* Root offers events first to widgets on top. */
-        iReverseForEach(PtrArray, i, data_Root()->onTop) {
+        iReverseForEach(PtrArray, i, get_Root()->onTop) {
             iWidget *widget = *i.value;
             if (isVisible_Widget(widget) && dispatchEvent_Widget(widget, ev)) {
 #if 0
@@ -774,7 +775,7 @@ iBool dispatchEvent_Widget(iWidget *d, const SDL_Event *ev) {
         }
     }
     else if (ev->type == SDL_MOUSEMOTION &&
-             (!data_Root()->hover || hasParent_Widget(d, data_Root()->hover)) &&
+             (!get_Root()->hover || hasParent_Widget(d, get_Root()->hover)) &&
              flags_Widget(d) & hover_WidgetFlag && ~flags_Widget(d) & hidden_WidgetFlag &&
              ~flags_Widget(d) & disabled_WidgetFlag) {
         if (contains_Widget(d, init_I2(ev->motion.x, ev->motion.y))) {
@@ -792,7 +793,7 @@ iBool dispatchEvent_Widget(iWidget *d, const SDL_Event *ev) {
            handle the events first. */
         iReverseForEach(ObjectList, i, d->children) {
             iWidget *child = as_Widget(i.object);
-            if (child == data_Root()->focus && isKeyboardEvent_(ev)) {
+            if (child == get_Root()->focus && isKeyboardEvent_(ev)) {
                 continue; /* Already dispatched. */
             }
             if (isVisible_Widget(child) && child->flags & keepOnTop_WidgetFlag) {
@@ -1081,7 +1082,7 @@ void drawChildren_Widget(const iWidget *d) {
     }
     /* Root draws the on-top widgets on top of everything else. */
     if (!d->parent) {
-        iConstForEach(PtrArray, i, onTop_RootData()) {
+        iConstForEach(PtrArray, i, onTop_Root(get_Root())) {
             const iWidget *top = *i.value;
             draw_Widget(top);
         }
@@ -1198,7 +1199,7 @@ iAny *hitChild_Widget(const iWidget *d, iInt2 coord) {
     }
     /* Check for on-top widgets first. */
     if (!d->parent) {
-        iReverseForEach(PtrArray, i, onTop_RootData()) {
+        iReverseForEach(PtrArray, i, onTop_Root(get_Root())) {
             iWidget *child = i.ptr;
 //            printf("ontop: %s (%s) hidden:%d hittable:%d\n", cstr_String(id_Widget(child)),
 //                   class_Widget(child)->name,
@@ -1286,12 +1287,12 @@ iBool isDisabled_Widget(const iAnyObject *d) {
 
 iBool isFocused_Widget(const iAnyObject *d) {
     iAssert(isInstance_Object(d, &Class_Widget));
-    return data_Root()->focus == d;
+    return get_Root()->focus == d;
 }
 
 iBool isHover_Widget(const iAnyObject *d) {
     iAssert(isInstance_Object(d, &Class_Widget));
-    return data_Root()->hover == d;
+    return get_Root()->hover == d;
 }
 
 iBool isSelected_Widget(const iAnyObject *d) {
@@ -1337,12 +1338,12 @@ iBool isAffectedByVisualOffset_Widget(const iWidget *d) {
 }
 
 void setFocus_Widget(iWidget *d) {
-    if (data_Root()->focus != d) {
-        if (data_Root()->focus) {
-            iAssert(!contains_PtrSet(data_Root()->pendingDestruction, data_Root()->focus));
-            postCommand_Widget(data_Root()->focus, "focus.lost");
+    if (get_Root()->focus != d) {
+        if (get_Root()->focus) {
+            iAssert(!contains_PtrSet(get_Root()->pendingDestruction, get_Root()->focus));
+            postCommand_Widget(get_Root()->focus, "focus.lost");
         }
-        data_Root()->focus = d;
+        get_Root()->focus = d;
         if (d) {
             iAssert(flags_Widget(d) & focusable_WidgetFlag);
             postCommand_Widget(d, "focus.gained");
@@ -1351,15 +1352,15 @@ void setFocus_Widget(iWidget *d) {
 }
 
 iWidget *focus_Widget(void) {
-    return data_Root()->focus;
+    return get_Root()->focus;
 }
 
 void setHover_Widget(iWidget *d) {
-    data_Root()->hover = d;
+    get_Root()->hover = d;
 }
 
 iWidget *hover_Widget(void) {
-    return data_Root()->hover;
+    return get_Root()->hover;
 }
 
 static const iWidget *findFocusable_Widget_(const iWidget *d, const iWidget *startFrom,
@@ -1403,7 +1404,7 @@ static const iWidget *findFocusRoot_Widget_(const iWidget *d) {
 }
 
 iAny *findFocusable_Widget(const iWidget *startFrom, enum iWidgetFocusDir focusDir) {
-    const iWidget *root = findFocusRoot_Widget_(get_Window()->root);
+    const iWidget *root = findFocusRoot_Widget_(get_Window()->root.widget);
     iAssert(root != NULL);
     iBool getNext = (startFrom ? iFalse : iTrue);
     const iWidget *found = findFocusable_Widget_(root, startFrom, &getNext, focusDir);
@@ -1415,14 +1416,14 @@ iAny *findFocusable_Widget(const iWidget *startFrom, enum iWidgetFocusDir focusD
 }
 
 void setMouseGrab_Widget(iWidget *d) {
-    if (data_Root()->mouseGrab != d) {
-        data_Root()->mouseGrab = d;
+    if (get_Root()->mouseGrab != d) {
+        get_Root()->mouseGrab = d;
         SDL_CaptureMouse(d != NULL);
     }
 }
 
 iWidget *mouseGrab_Widget(void) {
-    return data_Root()->mouseGrab;
+    return get_Root()->mouseGrab;
 }
 
 void postCommand_Widget(const iAnyObject *d, const char *cmd, ...) {
@@ -1456,7 +1457,7 @@ void refresh_Widget(const iAnyObject *d) {
 }
 
 void raise_Widget(iWidget *d) {
-    iPtrArray *onTop = onTop_RootData();
+    iPtrArray *onTop = onTop_Root(get_Root());
     if (d->flags & keepOnTop_WidgetFlag) {
         iAssert(indexOf_PtrArray(onTop, d) != iInvalidPos);
         removeOne_PtrArray(onTop, d);
diff --git a/src/ui/window.c b/src/ui/window.c
index ea2a4ec0..627f16b1 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -165,23 +165,21 @@ static void setupUserInterface_Window(iWindow *d) {
 #if defined (iPlatformAppleDesktop)
     insertMacMenus_();
 #endif
-    static iRootData rootData_;
-    setCurrent_Root(NULL, &rootData_);
-    d->root = createUserInterface_Root();
-    setCurrent_Root(d->root, &rootData_);
+    setCurrent_Root(&d->root);
+    createUserInterface_Root(&d->root);
 }
 
 static void updateRootSize_Window_(iWindow *d, iBool notifyAlways) {
-    iInt2 *size = &d->root->rect.size;
+    iInt2 *size = &d->root.widget->rect.size;
     const iInt2 oldSize = *size;
     SDL_GetRendererOutputSize(d->render, &size->x, &size->y);
     size->y -= d->keyboardHeight;
-    d->root->minSize = *size;
+    d->root.widget->minSize = *size;
     if (notifyAlways || !isEqual_I2(oldSize, *size)) {
-        updatePadding_Root(d->root);
+        updatePadding_Root(&d->root);
         const iBool isHoriz = (d->place.lastNotifiedSize.x != size->x);
         const iBool isVert  = (d->place.lastNotifiedSize.y != size->y);
-        arrange_Widget(d->root);
+        arrange_Widget(d->root.widget);
         postCommandf_App("window.resized width:%d height:%d horiz:%d vert:%d",
                          size->x,
                          size->y,
@@ -196,8 +194,8 @@ static void updateRootSize_Window_(iWindow *d, iBool notifyAlways) {
 void drawWhileResizing_Window(iWindow *d, int w, int h) {
     /* This is called while a window resize is in progress, so we can be pretty confident
        the size has actually changed. */
-    d->root->rect.size = coord_Window(d, w, h);
-    arrange_Widget(d->root);
+    d->root.widget->rect.size = coord_Window(d, w, h);
+    arrange_Widget(d->root.widget);
     draw_Window(d);
 }
 
@@ -347,7 +345,7 @@ static SDL_Surface *loadImage_(const iBlock *data, int resized) {
 void init_Window(iWindow *d, iRect rect) {
     theWindow_ = d;
     d->win = NULL;
-    d->root = NULL;
+    init_Root(&d->root);
     iZap(d->cursors);
     d->place.initialPos = rect.pos;
     d->place.normalRect = rect;
@@ -460,7 +458,7 @@ void deinit_Window(iWindow *d) {
             SDL_FreeCursor(d->cursors[i]);
         }
     }
-    iReleasePtr(&d->root);
+    deinit_Root(&d->root);
     deinit_Text();
     SDL_DestroyRenderer(d->render);
     SDL_DestroyWindow(d->win);
@@ -636,7 +634,7 @@ static iBool handleWindowEvent_Window_(iWindow *d, const SDL_WindowEvent *ev) {
             return iTrue;
         }
         case SDL_WINDOWEVENT_RESIZED:
-            updatePadding_Root(d->root);
+            updatePadding_Root(&d->root);
             if (d->isMinimized) {
                 updateRootSize_Window_(d, iTrue);
                 return iTrue;
@@ -768,7 +766,7 @@ iBool processEvent_Window(iWindow *d, const SDL_Event *ev) {
                 event.button.x = pos.x;
                 event.button.y = pos.y;
             }
-            iWidget *widget = d->root;
+            iWidget *widget = d->root.widget;
             if (event.type == SDL_MOUSEMOTION || event.type == SDL_MOUSEWHEEL ||
                 event.type == SDL_MOUSEBUTTONUP || event.type == SDL_MOUSEBUTTONDOWN) {
                 if (mouseGrab_Widget()) {
@@ -796,7 +794,7 @@ iBool processEvent_Window(iWindow *d, const SDL_Event *ev) {
                 }
             }
             if (isMetricsChange_UserEvent(&event)) {
-                updateMetrics_Root(d->root);
+                updateMetrics_Root(&d->root);
             }
             if (isCommand_UserEvent(&event, "lang.changed")) {
 #if defined (iPlatformAppleDesktop)
@@ -805,8 +803,8 @@ iBool processEvent_Window(iWindow *d, const SDL_Event *ev) {
                 insertMacMenus_();
 #endif
                 invalidate_Window_(d);
-                updatePreferencesLayout_Widget(findChild_Widget(d->root, "prefs"));
-                arrange_Widget(d->root);
+                updatePreferencesLayout_Widget(findChild_Widget(d->root.widget, "prefs"));
+                arrange_Widget(d->root.widget);
                 //printTree_Widget(findChild_Widget(d->root, "prefs"));
             }
             if (oldHover != hover_Widget()) {
@@ -823,7 +821,7 @@ iBool processEvent_Window(iWindow *d, const SDL_Event *ev) {
 
 iBool postContextClick_Window(iWindow *d, const SDL_MouseButtonEvent *ev) {
     /* A context menu may still get triggered here. */
-    const iWidget *hit = hitChild_Widget(d->root, init_I2(ev->x, ev->y));
+    const iWidget *hit = hitChild_Widget(d->root.widget, init_I2(ev->x, ev->y));
     while (hit && isEmpty_String(id_Widget(hit))) {
         hit = parent_Widget(hit);
     }
@@ -868,7 +866,7 @@ void draw_Window(iWindow *d) {
     /* Draw widgets. */
     d->frameTime = SDL_GetTicks();
     if (isExposed_Window(d)) {
-        draw_Widget(d->root);
+        draw_Widget(d->root.widget);
 #if defined (LAGRANGE_ENABLE_CUSTOM_FRAME)
         /* App icon. */
         const iWidget *appIcon = findChild_Widget(d->root, "winbar.icon");
@@ -907,7 +905,7 @@ void resize_Window(iWindow *d, int w, int h) {
 
 void setTitle_Window(iWindow *d, const iString *title) {
     SDL_SetWindowTitle(d->win, cstr_String(title));
-    iLabelWidget *bar = findChild_Widget(d->root, "winbar.title");
+    iLabelWidget *bar = findChild_Widget(d->root.widget, "winbar.title");
     if (bar) {
         updateText_LabelWidget(bar, title);
     }
@@ -942,7 +940,7 @@ uint32_t id_Window(const iWindow *d) {
 }
 
 iInt2 rootSize_Window(const iWindow *d) {
-    return d && d->root ? d->root->rect.size : zero_I2();
+    return d && d->root.widget ? d->root.widget->rect.size : zero_I2();
 }
 
 iRect safeRootRect_Window(const iWindow *d) {
diff --git a/src/ui/window.h b/src/ui/window.h
index 9d9a6aeb..f90bd863 100644
--- a/src/ui/window.h
+++ b/src/ui/window.h
@@ -22,7 +22,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 
 #pragma once
 
-#include "widget.h"
+#include "root.h"
 
 #include <the_Foundation/rect.h>
 #include <SDL_events.h>
@@ -66,8 +66,8 @@ struct Impl_Window {
     iBool         ignoreClick;
     uint32_t      focusGainedAt;
     SDL_Renderer *render;
-    iWidget *     root;
-    float         pixelRatio; /* conversion between points and pixels, e.g., coords, window size */
+    iRoot         root;         /* root widget and UI state */
+    float         pixelRatio;   /* conversion between points and pixels, e.g., coords, window size */
     float         displayScale; /* DPI-based scaling factor of current display, affects uiScale only */
     float         uiScale;
     uint32_t      frameTime;