basic example: ensure AutoScroller scrolls correctly when first opened

In AutoScroller.qml, the following line

    target: inputItem && !Qt.inputMethod.animating ? Qt.inputMethod : null

prevents onKeyboardRectangleChanged from getting executed. Even though
Qt.inputMethod.animating is updated before the rectangle is updated,
the handler still doesn't get emitted. Since the VKB only emits
keyboardRectangleChanged when the input method is not animating (see
the binding in Keyboard.qml), we can safely remove that check.

That just leaves one more issue: clicking in an input field, then
clicking outside of it (on the MouseArea) to hide the keyboard, then
clicking back in a lower text field will not cause AutoScroller
to scroll. In this case, onInputItemChanged is called, but the if
checks (mentioned at the top of the description of the bug report) use
the full height of the flickable before it's reduced to account for the
keyboard. Subtracting the height of the keyboardRectangle from the
flickable's height didn't work, so that issue needs to be fixed
separately.

Task-number: QTBUG-66294
Change-Id: I3733bb6be05443748eb873d76daee428be9687e8
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 39 insertions, 55 deletions

diff --git a/examples/virtualkeyboard/basic/Basic.qml b/examples/virtualkeyboard/basic/Basic.qml
index 158a7826..f3cd59c3 100644
--- a/examples/virtualkeyboard/basic/Basic.qml
+++ b/examples/virtualkeyboard/basic/Basic.qml
@@ -41,7 +41,7 @@ Rectangle {
     property bool handwritingInputPanelActive: false
 
     Flickable {
-        id: flickable
+        id: contentFlickable
         anchors.fill: parent
         contentWidth: content.width
         contentHeight: content.height
@@ -54,7 +54,7 @@ Rectangle {
 
         MouseArea  {
             id: content
-            width: flickable.width
+            width: contentFlickable.width
             height: textEditors.height + 24
 
             onClicked: focus = true
diff --git a/examples/virtualkeyboard/basic/basic-b2qt.qml b/examples/virtualkeyboard/basic/basic-b2qt.qml
index 59c64b86..1ab93b27 100644
--- a/examples/virtualkeyboard/basic/basic-b2qt.qml
+++ b/examples/virtualkeyboard/basic/basic-b2qt.qml
@@ -43,8 +43,9 @@ Item {
         height: Screen.width < Screen.height ? parent.width : parent.height
         anchors.centerIn: parent
         rotation: Screen.width < Screen.height ? 90 : 0
+
         Basic {
-            id: virtualKeyboard
+            id: contentContainer
             anchors.left: parent.left
             anchors.top: parent.top
             anchors.right: parent.right
diff --git a/examples/virtualkeyboard/basic/content/AutoScroller.qml b/examples/virtualkeyboard/basic/content/AutoScroller.qml
index d8d84a50..4893f133 100644
--- a/examples/virtualkeyboard/basic/content/AutoScroller.qml
+++ b/examples/virtualkeyboard/basic/content/AutoScroller.qml
@@ -31,77 +31,60 @@ import QtQuick 2.0
 import QtQuick.VirtualKeyboard 2.1
 
 Item {
+    property var flickable
+    readonly property var inputItem: InputContext.inputItem
 
-    property var innerFlickable
-    property var outerFlickable
-    property var inputItem: InputContext.inputItem
-
-    onInputItemChanged: {
-        innerFlickable = null
-        outerFlickable = null
-        if (inputItem !== null) {
-            var parent_ = inputItem.parent
-            while (parent_) {
-                if (parent_.maximumFlickVelocity) {
-                    if (innerFlickable) {
-                        outerFlickable = parent_
-                        break
-                    } else {
-                        innerFlickable = parent_
-                    }
-                }
-                parent_ = parent_.parent
-            }
-            delayedLoading.triggered()
-        }
-    }
+    onInputItemChanged: delayedLoading.start()
 
     function ensureVisible(flickable) {
-        if (Qt.inputMethod.visible && inputItem && flickable && flickable.visible && flickable.interactive) {
+        if (!Qt.inputMethod.visible || !inputItem || !flickable || !flickable.visible/* || !flickable.interactive*/)
+            return;
 
-            var verticallyFlickable = (flickable.flickableDirection === Flickable.HorizontalAndVerticalFlick || flickable.flickableDirection === Flickable.VerticalFlick
-                                       || (flickable.flickableDirection === Flickable.AutoFlickDirection && flickable.contentHeight > flickable.height))
-            var horizontallyFlickable = (flickable.flickableDirection === Flickable.HorizontalAndVerticalFlick || flickable.flickableDirection === Flickable.HorizontalFlick
-                                         || (flickable.flickableDirection === Flickable.AutoFlickDirection && flickable.contentWidth > flickable.width))
+        var verticallyFlickable = (flickable.flickableDirection === Flickable.HorizontalAndVerticalFlick || flickable.flickableDirection === Flickable.VerticalFlick
+                                   || (flickable.flickableDirection === Flickable.AutoFlickDirection && flickable.contentHeight > flickable.height))
+        var horizontallyFlickable = (flickable.flickableDirection === Flickable.HorizontalAndVerticalFlick || flickable.flickableDirection === Flickable.HorizontalFlick
+                                     || (flickable.flickableDirection === Flickable.AutoFlickDirection && flickable.contentWidth > flickable.width))
 
-            if ((!verticallyFlickable && !horizontallyFlickable) || !inputItem.hasOwnProperty("cursorRectangle"))
-                return
+        if ((!verticallyFlickable && !horizontallyFlickable) || !inputItem.hasOwnProperty("cursorRectangle"))
+            return
 
-            var cursorRectangle = flickable.contentItem.mapFromItem(inputItem, inputItem.cursorRectangle.x, inputItem.cursorRectangle.y)
+        var cursorRectangle = flickable.contentItem.mapFromItem(inputItem, inputItem.cursorRectangle.x, inputItem.cursorRectangle.y)
 
-            var oldContentY = flickable.contentY
-            if (verticallyFlickable) {
-                var scrollMarginVertical = (flickable && flickable.scrollMarginVertical) ? flickable.scrollMarginVertical : 10
-                if (flickable.contentY >= cursorRectangle.y  - scrollMarginVertical)
-                    flickable.contentY = Math.max(0, cursorRectangle.y  - scrollMarginVertical)
-                else if (flickable.contentY + flickable.height <= cursorRectangle.y  + inputItem.cursorRectangle.height + scrollMarginVertical)
-                    flickable.contentY = Math.min(flickable.contentHeight - flickable.height, cursorRectangle.y + inputItem.cursorRectangle.height - flickable.height + scrollMarginVertical)
+        if (verticallyFlickable) {
+            var scrollMarginVertical = flickable.scrollMarginVertical ? flickable.scrollMarginVertical : 10
+            if (flickable.contentY >= cursorRectangle.y - scrollMarginVertical) {
+                // The flickable is foo far down; move it up.
+                flickable.contentY = Math.max(0, cursorRectangle.y  - scrollMarginVertical)
+            } else if (flickable.contentY + flickable.height <= cursorRectangle.y  + inputItem.cursorRectangle.height + scrollMarginVertical) {
+                // The flickable is foo far up; move it down.
+                flickable.contentY = Math.min(flickable.contentHeight - flickable.height, cursorRectangle.y + inputItem.cursorRectangle.height - flickable.height + scrollMarginVertical)
             }
-            if (horizontallyFlickable) {
-                var scrollMarginHorizontal = (flickable && flickable.scrollMarginHorizontal) ? flickable.scrollMarginHorizontal : 10
-                if (flickable.contentX >= cursorRectangle.x - scrollMarginHorizontal)
-                    flickable.contentX = Math.max(0, cursorRectangle.x - scrollMarginHorizontal)
-                else if (flickable.contentX + flickable.width <= cursorRectangle.x + inputItem.cursorRectangle.width + scrollMarginHorizontal)
-                    flickable.contentX = Math.min(flickable.contentWidth - flickable.width, cursorRectangle.x + inputItem.cursorRectangle.width - flickable.width + scrollMarginHorizontal)
+        }
+        if (horizontallyFlickable) {
+            var scrollMarginHorizontal = flickable.scrollMarginHorizontal ? flickable.scrollMarginHorizontal : 10
+            if (flickable.contentX >= cursorRectangle.x - scrollMarginHorizontal) {
+                // The flickable is foo far down; move it up.
+                flickable.contentX = Math.max(0, cursorRectangle.x - scrollMarginHorizontal)
+            } else if (flickable.contentX + flickable.width <= cursorRectangle.x + inputItem.cursorRectangle.width + scrollMarginHorizontal) {
+                // The flickable is foo far up; move it down.
+                flickable.contentX = Math.min(flickable.contentWidth - flickable.width, cursorRectangle.x + inputItem.cursorRectangle.width - flickable.width + scrollMarginHorizontal)
             }
         }
     }
     Timer {
         id: delayedLoading
         interval: 10
-        onTriggered: {
-            ensureVisible(innerFlickable)
-            ensureVisible(outerFlickable)
-        }
+        onTriggered: ensureVisible(flickable)
     }
     Connections {
         ignoreUnknownSignals: true
-        target: inputItem && !Qt.inputMethod.animating ? Qt.inputMethod : null
-        onKeyboardRectangleChanged: delayedLoading.triggered()
+        target: Qt.inputMethod
+        onKeyboardRectangleChanged: delayedLoading.start()
     }
     Connections {
         ignoreUnknownSignals: true
-        target: inputItem && inputItem.activeFocus ? inputItem : null
-        onCursorRectangleChanged: delayedLoading.triggered()
+        target: inputItem
+        enabled: inputItem && inputItem.activeFocus
+        onCursorRectangleChanged: delayedLoading.start()
     }
 }