feat: video decoding configuration

Allows to set the following using Plasma's Session Environment Variables

QT_FFMPEG_DECODING_HW_DEVICE_TYPES
QT_MEDIA_BACKEND
LIBVA_DRIVER_NAME unclear if it does anything
VDPAU_DRIVER unclear if it does anything

https://wiki.archlinux.org/title/Hardware_video_acceleration
https://doc.qt.io/qt-6/advanced-ffmpeg-configuration.html
https://doc.qt.io/qt-6/qtmultimedia-index.html
https://userbase.kde.org/Session_Environment_Variables
https://wiki.archlinux.org/title/Environment_variables

Author: luisbocanegra

package/contents/ui/EnvironmentVariableModel.qml

@@ -0,0 +1,107 @@
+import QtQuick
+
+// import "code/utils.js" as Utils
+
+Item {
+    id: root
+    property ListModel model: ListModel {}
+    property bool isLoading: true
+    readonly property string plasmaEnvFile: "$HOME/.config/plasma-workspace/env/luisbocanegra.smart.video.wallpaper.reborn.sh"
+
+    signal updated
+    signal loaded
+
+    function initModel(envVars) {
+        model.clear();
+        let varList = envVars.split("\n");
+        for (let envVar of varList) {
+            let [name, value] = envVar.split("=");
+            const existsIndex = getIndex(name);
+            if (existsIndex !== -1) {
+                model.set(existsIndex, {
+                    name,
+                    value
+                });
+                continue;
+            }
+            model.append({
+                name,
+                value
+            });
+        }
+        root.isLoading = false;
+        loaded();
+    }
+
+    function getValue(name) {
+        for (let i = 0; i < model.count; i++) {
+            const item = model.get(i);
+            if (item.name === name) {
+                return item.value;
+            }
+        }
+        return "";
+    }
+
+    function getIndex(name) {
+        for (let i = 0; i < model.count; i++) {
+            const item = model.get(i);
+            if (item.name === name) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    function getPlasmaEnvVar(name, c) {
+        runCommand.exec(`grep 'export ${name}' "${plasmaEnvFile}" | sed 's/export ${name}=//'`, output => {
+            if (c) {
+                if (output.exitCode === 0 && output.stdout.length > 0) {
+                    return c(output.stdout.trim());
+                }
+                return c(null);
+            }
+        });
+    }
+
+    function setPlasmaEnvVar(name, value) {
+        // check if it exists
+        //   if it does replace
+        //   if it does not, append
+        runCommand.exec(`grep 'export ${name}' "${plasmaEnvFile}"`, output => {
+            if (output.exitCode === 0 && output.stdout.length > 0) {
+                console.log(`${name}`, output.stdout);
+                console.log(`sed -i 's/export ${name}=.*/export ${name}=${value}/g' "${plasmaEnvFile}"`);
+                runCommand.exec(`sed -i 's/export ${name}=.*/export ${name}=${value}/g' "${plasmaEnvFile}"`);
+            } else {
+                runCommand.exec(`touch "${plasmaEnvFile}" && echo "export ${name}=${value}" >> "${plasmaEnvFile}"`);
+            }
+        });
+    }
+
+    function removePlasmaEnvVar(name) {
+        console.log(`sed -i '/export ${name}=.*/d' "${plasmaEnvFile}"`);
+        runCommand.exec(`sed -i '/export ${name}=.*/d' "${plasmaEnvFile}"`);
+    }
+
+    function varExists(name) {
+        return getValue(name) !== "";
+    }
+
+    RunCommand {
+        id: runCommand
+    }
+
+    function getVars() {
+        let vars;
+        runCommand.exec(`printenv`, output => {
+            if (output.exitCode === 0 && output.stdout.length > 0) {
+                initModel(output.stdout.trim());
+            }
+        });
+    }
+
+    Component.onCompleted: {
+        getVars();
+    }
+}