Improve the layout selector UI

Changes:
* Now we use the "user data" icon as the button to expand the layouts
  combobox
* Added a tooltip to this icon
* Added buttons to configure the Timeline position in the same
  combobox
* Fixed some bugs in Dock using space for hidden widgets

data/strings/en.ini

@@ -1205,6 +1205,9 @@ help_twitter = Twitter
 help_enter_license = Enter &License
 help_about = &About
 
+[main_window]
+layout = User Interface Layout
+
 [mask_by_color]
 title = Select Color
 label_color = Color:

src/app/ui/configure_timeline_popup.cpp

@@ -53,7 +53,8 @@ ConfigureTimelinePopup::ConfigureTimelinePopup()
   m_box = new app::gen::TimelineConf();
   addChild(m_box);
 
-  m_box->position()->ItemChange.connect([this] { onChangePosition(); });
+  m_box->position()->ItemChange.connect(
+    [this] { onChangeTimelinePosition(m_box->position()->selectedItem()); });
   m_box->firstFrame()->Change.connect([this] { onChangeFirstFrame(); });
   m_box->merge()->Click.connect([this] { onChangeType(); });
   m_box->tint()->Click.connect([this] { onChangeType(); });
@@ -147,12 +148,12 @@ bool ConfigureTimelinePopup::onProcessMessage(ui::Message* msg)
   return PopupWindow::onProcessMessage(msg);
 }
 
-void ConfigureTimelinePopup::onChangePosition()
+void ConfigureTimelinePopup::onChangeTimelinePosition(int option)
 {
   gen::TimelinePosition newTimelinePos = gen::TimelinePosition::BOTTOM;
 
-  int selITem = m_box->position()->selectedItem();
-  switch (selITem) {
+  int selItem = option;
+  switch (selItem) {
     case 0: newTimelinePos = gen::TimelinePosition::LEFT; break;
     case 1: newTimelinePos = gen::TimelinePosition::RIGHT; break;
     case 2: newTimelinePos = gen::TimelinePosition::BOTTOM; break;

src/app/ui/configure_timeline_popup.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2025  Igara Studio S.A.
+// Copyright (C) 2022-2025  Igara Studio S.A.
 // Copyright (C) 2001-2017  David Capello
 //
 // This program is distributed under the terms of
@@ -31,9 +31,10 @@ class ConfigureTimelinePopup : public ui::PopupWindow {
 public:
   ConfigureTimelinePopup();
 
+  static void onChangeTimelinePosition(int option);
+
 protected:
   bool onProcessMessage(ui::Message* msg) override;
-  void onChangePosition();
   void onChangeFirstFrame();
   void onChangeType();
   void onOpacity();

src/app/ui/dock.cpp

@@ -227,17 +227,16 @@ void Dock::onSizeHint(ui::SizeHintEvent& ev)
 {
   gfx::Size sz = border().size();
 
-  if (m_sides[kLeftIndex])
+  if (hasVisibleSide(kLeftIndex))
     sz.w += m_sides[kLeftIndex]->sizeHint().w + childSpacing();
-  if (m_sides[kRightIndex])
+  if (hasVisibleSide(kRightIndex))
     sz.w += m_sides[kRightIndex]->sizeHint().w + childSpacing();
-  if (m_sides[kTopIndex])
+  if (hasVisibleSide(kTopIndex))
     sz.h += m_sides[kTopIndex]->sizeHint().h + childSpacing();
-  if (m_sides[kBottomIndex])
+  if (hasVisibleSide(kBottomIndex))
     sz.h += m_sides[kBottomIndex]->sizeHint().h + childSpacing();
-  if (m_sides[kCenterIndex]) {
+  if (hasVisibleSide(kCenterIndex))
     sz += m_sides[kCenterIndex]->sizeHint();
-  }
 
   ev.setSizeHint(sz);
 }

src/app/ui/dock.h

@@ -72,6 +72,8 @@ private:
                                       const gfx::Rect& separator,
                                       const int index)> f);
 
+  bool hasVisibleSide(const int i) const { return (m_sides[i] && m_sides[i]->isVisible()); }
+
   std::array<Widget*, kSides> m_sides;
   std::array<int, kSides> m_aligns;
   std::array<gfx::Size, kSides> m_sizes;

src/app/ui/layout_selector.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2021  Igara Studio S.A.
+// Copyright (C) 2021-2022  Igara Studio S.A.
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -11,10 +11,14 @@
 #include "app/ui/layout_selector.h"
 
 #include "app/app.h"
+#include "app/i18n/strings.h"
+#include "app/ui/button_set.h"
+#include "app/ui/configure_timeline_popup.h"
 #include "app/ui/main_window.h"
 #include "app/ui/separator_in_view.h"
 #include "app/ui/skin/skin_theme.h"
 #include "ui/listitem.h"
+#include "ui/tooltips.h"
 #include "ui/window.h"
 
 #define ANI_TICKS 5
@@ -49,6 +53,41 @@ private:
   LayoutId m_id;
 };
 
+// TODO Similar ButtonSet to the one in timeline_conf.xml
+class TimelineButtons : public ButtonSet {
+public:
+  TimelineButtons() : ButtonSet(2)
+  {
+    addItem(Strings::timeline_conf_left())->processMnemonicFromText();
+    addItem(Strings::timeline_conf_right())->processMnemonicFromText();
+    addItem(Strings::timeline_conf_bottom(), 2)->processMnemonicFromText();
+
+    Preferences::instance().general.timelinePosition.AfterChange.connect(
+      [this](gen::TimelinePosition position) {
+        int selItem = 0;
+        switch (position) {
+          case gen::TimelinePosition::LEFT:   selItem = 0; break;
+          case gen::TimelinePosition::RIGHT:  selItem = 1; break;
+          case gen::TimelinePosition::BOTTOM: selItem = 2; break;
+        }
+        setSelectedItem(selItem, false);
+      });
+
+    InitTheme.connect([this] {
+      auto theme = skin::SkinTheme::get(this);
+      setStyle(theme->styles.separatorInView());
+    });
+    initTheme();
+  }
+
+private:
+  void onItemChange(Item* item) override
+  {
+    ButtonSet::onItemChange(item);
+    ConfigureTimelinePopup::onChangeTimelinePosition(selectedItem());
+  }
+};
+
 }; // namespace
 
 void LayoutSelector::LayoutComboBox::onChange()
@@ -58,7 +97,8 @@ void LayoutSelector::LayoutComboBox::onChange()
   }
 }
 
-LayoutSelector::LayoutSelector() : m_button("", "\xc3\xb7")
+LayoutSelector::LayoutSelector(TooltipManager* tooltipManager)
+  : m_button(SkinTheme::instance()->parts.iconUserData())
 {
   m_button.Click.connect([this]() { switchSelector(); });
 
@@ -66,6 +106,15 @@ LayoutSelector::LayoutSelector() : m_button("", "\xc3\xb7")
 
   addChild(&m_comboBox);
   addChild(&m_button);
+
+  setupTooltips(tooltipManager);
+
+  InitTheme.connect([this] {
+    noBorderNoChildSpacing();
+    m_comboBox.noBorderNoChildSpacing();
+    m_button.noBorderNoChildSpacing();
+  });
+  initTheme();
 }
 
 LayoutSelector::~LayoutSelector()
@@ -80,8 +129,8 @@ void LayoutSelector::onAnimationFrame()
     case ANI_EXPANDING:
     case ANI_COLLAPSING: {
       const double t = animationTime();
-      m_comboBox.setSizeHint(gfx::Size((1.0 - t) * m_startSize.w + t * m_endSize.w,
-                                       (1.0 - t) * m_startSize.h + t * m_endSize.h));
+      m_comboBox.setSizeHint(gfx::Size(int(inbetween(m_startSize.w, m_endSize.w, t)),
+                                       int(inbetween(m_startSize.h, m_endSize.h, t))));
       break;
     }
   }
@@ -112,8 +161,11 @@ void LayoutSelector::switchSelector()
 
     // Create the combobox for first time
     if (m_comboBox.getItemCount() == 0) {
+      m_comboBox.addItem(new SeparatorInView("Layout", HORIZONTAL));
       m_comboBox.addItem(new LayoutItem(LayoutId::DEFAULT, "Default"));
       m_comboBox.addItem(new LayoutItem(LayoutId::DEFAULT_MIRROR, "Default / Mirror"));
+      m_comboBox.addItem(new SeparatorInView("Timeline", HORIZONTAL));
+      m_comboBox.addItem(new TimelineButtons());
     }
 
     m_comboBox.setVisible(true);
@@ -131,4 +183,9 @@ void LayoutSelector::switchSelector()
   startAnimation((expand ? ANI_EXPANDING : ANI_COLLAPSING), ANI_TICKS);
 }
 
+void LayoutSelector::setupTooltips(TooltipManager* tooltipManager)
+{
+  tooltipManager->addTooltipFor(&m_button, Strings::main_window_layout(), TOP);
+}
+
 } // namespace app

src/app/ui/layout_selector.h

@@ -9,13 +9,17 @@
 #pragma once
 
 #include "app/ui/dockable.h"
+#include "app/ui/icon_button.h"
 #include "ui/animated_widget.h"
 #include "ui/box.h"
 #include "ui/combobox.h"
-#include "ui/link_label.h"
 
 #include <memory>
 
+namespace ui {
+class TooltipManager;
+}
+
 namespace app {
 
 class LayoutSelector : public ui::HBox,
@@ -32,19 +36,20 @@ class LayoutSelector : public ui::HBox,
   };
 
 public:
-  LayoutSelector();
+  LayoutSelector(ui::TooltipManager* tooltipManager);
   ~LayoutSelector();
 
   // Dockable impl
   int dockableAt() const override { return ui::TOP | ui::BOTTOM; }
 
 private:
+  void setupTooltips(ui::TooltipManager* tooltipManager);
   void onAnimationFrame() override;
   void onAnimationStop(int animation) override;
   void switchSelector();
 
   LayoutComboBox m_comboBox;
-  ui::LinkLabel m_button;
+  IconButton m_button;
   gfx::Size m_startSize;
   gfx::Size m_endSize;
 };

src/app/ui/main_window.cpp

@@ -93,7 +93,6 @@ MainWindow::MainWindow()
   , m_tooltipManager(new TooltipManager)
   , m_dock(new Dock)
   , m_customizableDock(new Dock)
-  , m_layoutSelector(new LayoutSelector)
   , m_mode(NormalMode)
   , m_homeView(nullptr)
   , m_scalePanic(nullptr)
@@ -117,7 +116,7 @@ MainWindow::MainWindow()
 void MainWindow::initialize()
 {
   m_menuBar = std::make_unique<MainMenuBar>();
-  m_layoutSelector = std::make_unique<LayoutSelector>();
+  m_layoutSelector = std::make_unique<LayoutSelector>(m_tooltipManager);
 
   // Register commands to load menus+shortcuts for these commands
   Editor::registerCommands();