Organize project files

Put QML components into folders, remove unused ones, split __init__.py
with engine.py.

harmonyqml/components/chat/SendBox.qml

@@ -0,0 +1,63 @@
+import QtQuick 2.7
+import QtQuick.Controls 2.2
+import QtQuick.Layouts 1.4
+import "../base" as Base
+
+Rectangle {
+    function setFocus() { textArea.forceActiveFocus() }
+
+    id: "root"
+    Layout.fillWidth: true
+    Layout.minimumHeight: 32
+    Layout.preferredHeight: textArea.implicitHeight
+    // parent.height / 2 causes binding loop?
+    Layout.maximumHeight: pageStack.height / 2
+    color: "#BBB"
+
+    RowLayout {
+        anchors.fill: parent
+        spacing: 0
+
+        Base.Avatar {
+            id: "avatar"
+            username: chatPage.user.display_name
+            dimmension: root.Layout.minimumHeight
+            //visible: textArea.text === ""
+            visible: textArea.height <= root.Layout.minimumHeight
+        }
+
+        ScrollView {
+            Layout.fillHeight: true
+            Layout.fillWidth: true
+            id: sendBoxScrollView
+            clip: true
+
+            TextArea {
+                id: textArea
+                placeholderText: qsTr("Type a message...")
+                wrapMode: TextEdit.Wrap
+                selectByMouse: true
+                font.family: "Roboto"
+                font.pixelSize: 16
+                focus: true
+
+                Keys.onReturnPressed: {
+                    event.accepted = true
+
+                    if (event.modifiers & Qt.ShiftModifier ||
+                        event.modifiers & Qt.ControlModifier ||
+                        event.modifiers & Qt.AltModifier) {
+                        textArea.insert(textArea.cursorPosition, "\n")
+                        return
+                    }
+
+                    Backend.sendMessage(chatPage.user.user_id,
+                                        chatPage.room.room_id,
+                                        textArea.text)
+                    textArea.clear()
+                }
+                Keys.onEnterPressed: Keys.onReturnPressed(event)  // numpad enter
+            }
+        }
+    }
+}