Rework keyboard focus strategy

Keeping the focus in the search field doesn't work anymore. Instead, make
it possible for the focus to go back and forth properly.

BUG: 388835

discover/qml/DiscoverDrawer.qml

@@ -53,19 +53,21 @@ Kirigami.GlobalDrawer {
             Navigation.openHome()
     }
 
+    function suggestSearchText(text) {
+        toploader.item.text = text
+        toploader.item.forceActiveFocus()
+    }
     topContent: ConditionalLoader {
         id: toploader
         condition: drawer.wideScreen
         Layout.fillWidth: true
         componentFalse: Item {
             Layout.minimumHeight: 1
-            Keys.forwardTo: [window.pageStack]
         }
         componentTrue: SearchField {
             id: searchField
 
             visible: window.leftPage && (window.leftPage.searchFor != null || window.leftPage.hasOwnProperty("search"))
-            Keys.forwardTo: [window.pageStack]
 
             page: window.leftPage
 
@@ -76,6 +78,7 @@ Kirigami.GlobalDrawer {
                     Navigation.openApplicationList( { search: currentSearchText })
                 } else {
                     curr.search = currentSearchText;
+                    curr.forceActiveFocus()
                 }
             }
         }

discover/qml/DiscoverPage.qml

@@ -57,4 +57,11 @@ Kirigami.ScrollablePage
                 root.refreshing = true
         }
     }
+
+    readonly property var readableCharacters: /\w+/
+    Keys.onPressed: {
+        if(event.text.length > 0 && event.modifiers === Qt.NoModifier && event.text.match(readableCharacters)) {
+            window.globalDrawer.suggestSearchText(event.text)
+        }
+    }
 }

discover/qml/DiscoverWindow.qml

@@ -197,7 +197,6 @@ Kirigami.ApplicationWindow
 
     globalDrawer: DiscoverDrawer {
         wideScreen: window.wideScreen
-        focus: true
     }
 
     onCurrentTopLevelChanged: {

discover/qml/SearchField.qml

@@ -40,8 +40,6 @@ TextField
     }
     onAccepted: currentSearchText = text
 
-    Component.onCompleted: forceActiveFocus()
-
     hoverEnabled: true
     ToolTip {
         delay: Kirigami.Units.longDuration

discover/qml/SearchPage.qml

@@ -35,6 +35,7 @@ ApplicationsListPage {
     listHeaderExtra: SearchField {
         id: searchField
         focus: true
+        Component.onCompleted: forceActiveFocus()
 
         Connections {
             ignoreUnknownSignals: true