Add PCN theme system

Coexist with the old theme system for now. QML components have to be
updated to use the new system.

src/gui/Base/Class.qml

@@ -0,0 +1,8 @@
+// Copyright Mirage authors & contributors <https://github.com/mirukana/mirage>
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+import QtQuick 2.12
+
+QtObject {
+    property string name
+}

src/gui/Base/HButton.qml

@@ -8,10 +8,15 @@ import QtQuick.Layouts 1.12
 Button {
     id: button
 
+    property Theme ntheme: Theme {
+        target: button
+        classes: Class { name: "Button" }
+    }
+
     readonly property alias iconItem: contentItem.icon
     readonly property alias label: contentItem.label
 
-    property color backgroundColor: theme.controls.button.background
+    property color backgroundColor: ntheme.data.background
     property color focusLineColor:
         Qt.colorEqual(icon.color, theme.icons.colorize) ?
         theme.controls.button.focusedBorder :

src/gui/Base/Theme.qml

@@ -0,0 +1,25 @@
+// Copyright Mirage authors & contributors <https://github.com/mirukana/mirage>
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+import QtQuick 2.12
+
+QtObject {
+    id: root
+
+    property Item target
+    default property list<Class> classes
+
+    readonly property var matchablePathRegex: utils.getClassPathRegex(target)
+    readonly property var themeRules: window.themeRules
+    readonly property var data: {
+        const newData = {}
+
+        for (const [path, section] of Object.entries(themeRules))
+            if (matchablePathRegex.test(path))
+                for (const [name, value] of Object.entries(section))
+                    if (! name.startsWith("_"))
+                        newData[name] = value
+
+        return newData
+    }
+}

src/gui/MainPane/BottomBar.qml

@@ -22,7 +22,6 @@ Rectangle {
             id: addAccountButton
             icon.name: "add-account"
             toolTip.text: qsTr("Add another account")
-            backgroundColor: theme.mainPane.bottomBar.settingsButtonBackground
             onClicked: {
                 pageLoader.show("Pages/AddAccount/AddAccount.qml")
                 roomList.startCorrectItemSearch()

src/gui/Pages/Chat/Composer/Composer.qml

@@ -8,6 +8,13 @@ import "../../../Base"
 import "../AutoCompletion"
 
 Rectangle {
+    id: composer
+
+    property Theme ntheme: Theme {
+        target: composer
+        classes: Class { name: "Composer" }
+    }
+
     property UserAutoCompletion userCompletion
     property alias eventList: messageArea.eventList
 

src/gui/Pages/Chat/Composer/UploadButton.qml

@@ -8,9 +8,10 @@ import "../../../Base"
 import "../../../Dialogs"
 
 HButton {
+    ntheme.classes: Class { name: "UploadButton" }
+
     enabled: chat.roomInfo.can_send_messages
     icon.name: "upload-file"
-    backgroundColor: theme.chat.composer.uploadButton.background
     toolTip.text:
         chat.userInfo.max_upload_size ?
         qsTr("Send files (%1 max)").arg(

src/gui/Pages/Chat/RoomPane/MemberView/MemberView.qml

@@ -149,8 +149,6 @@ HColumnLayout {
                 HButton {
                     id: inviteButton
                     icon.name: "room-send-invite"
-                    backgroundColor:
-                        theme.chat.roomPane.bottomBar.inviteButton.background
                     enabled:
                         chat.userInfo.presence !== "offline" &&
                         chat.roomInfo.can_invite

src/gui/PythonBridge/EventHandlers.qml

@@ -73,6 +73,7 @@ QtObject {
         }
 
         type === "Settings" ? window.settings = newData :
+        type === "NewTheme" ? window.themeRules = newData :
         type === "UIState" ? window.uiState = newData :
         type === "History" ? window.history = newData :
         null

src/gui/PythonBridge/PythonRootBridge.qml

@@ -21,12 +21,13 @@ PythonBridge {
         addImportPath("qrc:/src")
 
         importNames("backend.qml_bridge", ["BRIDGE"], () => {
-            callCoro("get_settings", [], ([settings, state, hist, theme]) => {
-                window.settings = settings
-                window.uiState  = state
-                window.history  = hist
-                window.theme    = Qt.createQmlObject(theme, window, "theme")
-                utils.theme     = window.theme
+            callCoro("get_settings", [], ([settings, state, hist, theme, themeRules]) => {
+                window.settings   = settings
+                window.uiState    = state
+                window.history    = hist
+                window.theme      = Qt.createQmlObject(theme, window, "theme")
+                utils.theme       = window.theme
+                window.themeRules = themeRules
 
                 callCoro("saved_accounts.any_saved", [], any => {
                     if (any) { callCoro("load_saved_accounts", []) }

src/gui/Utils.qml

@@ -519,4 +519,27 @@ QtObject {
 
         return {word, start, end: seen}
     }
+
+    function getClassPathRegex(obj) {
+        const regexParts = []
+        let parent       = obj
+
+        while (parent) {
+            if (! parent.ntheme || ! parent.ntheme.classes.length) {
+                parent = parent.parent
+                continue
+            }
+
+            const names = []
+            const end   = regexParts.length ? "\\.)?" : ")"
+
+            for (let i = 0; i < parent.ntheme.classes.length; i++)
+                names.push(parent.ntheme.classes[i].name)
+
+            regexParts.push("(" + names.join("|") + end)
+            parent = parent.parent
+        }
+
+        return new RegExp("^" + regexParts.reverse().join("") + "$")
+    }
 }

src/gui/Window.qml

@@ -28,6 +28,7 @@ ApplicationWindow {
     property var uiState: ({})
     property var history: ({})
     property var theme: null
+    property var themeRules: null
     property string settingsFolder
 
     readonly property var visibleMenus: ({})