Simplify startup and improve its animation

- Remove Python.loadingAccounts/willLoadAccounts
- Fix HPage SwipeView bug that caused its inner SidePane to steal focus

- Use overshoot for animation
- Get rid of sidepane flickering
- Set default HNumberAnimation easing.type to OutQuad, specify InOutQuad
  for HCheckBox

TODO.md

@@ -2,7 +2,6 @@
   - `^property type name$`
   - Use [Animators](https://doc.qt.io/qt-5/qml-qtquick-animator.html)
     - Choose a better default easing type for animations
-    - Use overshoot for the scale login thing
   - Sendbox
   - HButton
     - Control: hovered, visualFocus, enaled

src/qml/Base/HCheckBox.qml

@@ -30,7 +30,12 @@ CheckBox {
 
             visible: scale > 0
             scale: box.checked ? 1 : 0
-            Behavior on scale { HNumberAnimation { overshoot: 4 } }
+            Behavior on scale {
+                HNumberAnimation {
+                    overshoot: 4
+                    easing.type: Easing.InOutBack
+                }
+            }
         }
     }
 

src/qml/Base/HNumberAnimation.qml

@@ -1,10 +1,10 @@
 import QtQuick 2.12
 
 NumberAnimation {
-    property real factor: Math.max(overshoot / 1.75, 1.0)
+    property real factor: 1.0
     property real overshoot: 1.0
 
-    duration: theme.animationDuration * factor
-    easing.type: overshoot > 1 ? Easing.InOutBack : Easing.Linear
+    duration: theme.animationDuration * Math.max(overshoot / 1.7, 1.0) * factor
+    easing.type: overshoot > 1 ? Easing.OutBack : Easing.Linear
     easing.overshoot: overshoot
 }

src/qml/Base/HPage.qml

@@ -18,12 +18,13 @@ SwipeView {
         Math.min(theme.spacing * width / 400, theme.spacing)
 
     id: swipeView
-    currentIndex: 1
     clip: true
     interactive: sidePane.reduce
+    currentIndex: 1
 
     SidePane {
         implicitWidth: swipeView.width
+        animateWidth: false  // Without this, the SidePane gets auto-focused
         collapse: false
         reduce: false
         visible: swipeView.interactive

src/qml/Python.qml

@@ -7,11 +7,9 @@ Python {
     id: py
 
     property bool ready: false
+    property bool startupAnyAccountsSaved: false
     property var pendingCoroutines: ({})
 
-    signal willLoadAccounts(bool will)
-    property bool loadingAccounts: false
-
     function callSync(name, args=[]) {
         return call_sync("APP.backend." + name, args)
     }
@@ -59,15 +57,10 @@ Python {
         importNames("python", ["APP"], () => {
             loadSettings(() => {
                 callCoro("saved_accounts.any_saved", [], any => {
-                    py.ready = true
-                    willLoadAccounts(any)
+                    if (any) { py.callCoro("load_saved_accounts", []) }
 
-                    if (any) {
-                        py.loadingAccounts = true
-                        py.callCoro("load_saved_accounts", [], () => {
-                            py.loadingAccounts = false
-                        })
-                    }
+                    py.startupAnyAccountsSaved = any
+                    py.ready                   = true
                 })
             })
         })

src/qml/SidePane/SidePane.qml

@@ -14,6 +14,7 @@ HRectangle {
     property bool manuallyResizing: false
     property bool manuallyResized: false
     property int manualWidth: 0
+    property bool animateWidth: true
 
     Component.onCompleted: {
         if (window.uiState.sidePaneManualWidth) {
@@ -61,7 +62,9 @@ HRectangle {
         0 : theme.spacing
 
     Behavior on currentSpacing { HNumberAnimation {} }
-    Behavior on implicitWidth  { HNumberAnimation {} }
+    Behavior on implicitWidth  {
+        HNumberAnimation { factor: animateWidth ? 1 : 0 }
+    }
 
 
     HColumnLayout {

src/qml/UI.qml

@@ -22,27 +22,9 @@ HRectangle {
         }
     }
 
-    Connections {
-        target: py
-        onWillLoadAccounts: will => {
-            if (! will) {
-                pageStack.showPage("SignIn")
-                return
-            }
-
-            let page  = window.uiState.page
-            let props = window.uiState.pageProperties
-
-            if (page == "Chat/Chat.qml") {
-                pageStack.showRoom(props.userId, props.roomId)
-            } else {
-                pageStack.show(page, props)
-            }
-        }
-    }
-
     property bool accountsPresent:
-        (modelSources["Account"] || []).length > 0 || py.loadingAccounts
+        (modelSources["Account"] || []).length > 0 ||
+        py.startupAnyAccountsSaved
 
     HImage {
         id: mainUIBackground
@@ -74,7 +56,7 @@ HRectangle {
             width: implicitWidth
             Layout.minimumWidth: reduce ? 0 : theme.sidePane.collapsedWidth
             Layout.maximumWidth:
-                window.width -theme.minimumSupportedWidthPlusSpacing
+                window.width - theme.minimumSupportedWidthPlusSpacing
 
             Behavior on Layout.minimumWidth { HNumberAnimation {} }
         }
@@ -83,6 +65,22 @@ HRectangle {
             id: pageStack
             property bool isWide: width > theme.contentIsWideAbove
 
+            Component.onCompleted: {
+                if (! py.startupAnyAccountsSaved) {
+                    pageStack.showPage("SignIn")
+                    return
+                }
+
+                let page  = window.uiState.page
+                let props = window.uiState.pageProperties
+
+                if (page == "Chat/Chat.qml") {
+                    pageStack.showRoom(props.userId, props.roomId)
+                } else {
+                    pageStack.show(page, props)
+                }
+            }
+
             function show(componentUrl, properties={}) {
                 pageStack.replace(componentUrl, properties)
             }

src/qml/Window.qml

@@ -43,6 +43,6 @@ ApplicationWindow {
         scale: py.ready ? 1 : 0.5
         source: py.ready ? "UI.qml" : ""
 
-        Behavior on scale { HNumberAnimation {} }
+        Behavior on scale { HNumberAnimation { overshoot: 5; factor: 1.2 } }
     }
 }