Show a warning dialog in case we are going to erase drive > 32GB

It can happen that the user connects a drive by mistake or forgets to
disconnect it, and it's unfortunate if the drive is accidentally erased.
In this case, display a warning dialogue that the user is using a drive
larger than 32GB.

Fixes #742

src/app/qml.qrc

@@ -3,6 +3,7 @@
         <file>qml/AboutDialog.qml</file>
         <file>qml/CancelDialog.qml</file>
         <file>qml/DownloadPage.qml</file>
+        <file>qml/DeviceWarningDialog.qml</file>
         <file>qml/DrivePage.qml</file>
         <file>qml/Heading.qml</file>
         <file>qml/MainPage.qml</file>

src/app/qml/DeviceWarningDialog.qml

@@ -0,0 +1,95 @@
+/*
+ * Fedora Media Writer
+ * Copyright (C) 2024 Jan Grulich <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+import QtQuick 6.6
+import QtQuick.Controls 6.6
+import QtQuick.Window 6.6
+import QtQuick.Layouts 6.6
+
+ApplicationWindow {
+    id: cancelDialog
+
+    minimumWidth: Math.max(360, units.gridUnit * 20)
+    maximumWidth: Math.max(360, units.gridUnit * 20)
+    minimumHeight: Math.max(180, units.gridUnit * 10)
+    maximumHeight: Math.max(180, units.gridUnit * 10)
+
+    modality: Qt.ApplicationModal
+    x: Screen.width / 2 - width / 2
+    y: Screen.height / 2 - height / 2
+    title: " "
+
+    ColumnLayout {
+        id: mainColumn
+        anchors {
+            fill: parent
+            margins: units.gridUnit
+        }
+        spacing: units.gridUnit
+
+        Heading {
+            level: 2
+            Layout.fillWidth: true
+            Layout.leftMargin: units.gridUnit
+            Layout.rightMargin: units.gridUnit
+            text: "Erase confirmation"
+        }
+
+        Label {
+            Layout.fillWidth: true
+            Layout.leftMargin: units.gridUnit
+            Layout.rightMargin: units.gridUnit
+            text: qsTr("The device you have selected appears to be larger than 32GB. Are you sure you want to completely erase all the data on it?")
+            wrapMode: Label.Wrap
+        }
+
+        RowLayout {
+            Layout.alignment: Qt.AlignBottom
+            Layout.fillHeight: true
+
+            Item {
+                Layout.fillWidth: true
+            }
+
+            Button {
+                id: cancelButton
+                onClicked: cancelDialog.close()
+                text: qsTr("Cancel")
+            }
+
+            Button {
+                id: continueButton
+                onClicked: {
+                    cancelDialog.close()
+                    selectedPage = Units.Page.DownloadPage
+                    drives.selected.setImage(releases.variant)
+                    drives.selected.write(releases.variant)
+                }
+                text: {
+                    if (selectedOption == Units.MainSelect.Write || downloadManager.isDownloaded(releases.selected.version.variant.url))
+                        return qsTr("Write")
+                    if (Qt.platform.os === "windows" || Qt.platform.os === "osx")
+                        return qsTr("Download && Write")
+                    return qsTr("Download & Write")
+                }
+            }
+        }
+    }
+}
+

src/app/qml/DrivePage.qml

@@ -182,12 +182,22 @@ Page {
     }
 
     onNextButtonClicked: {
-        selectedPage = Units.Page.DownloadPage
         if (selectedOption != Units.MainSelect.Write)
             releases.variant.download()
-        if (drives.length) {
-            drives.selected.setImage(releases.variant)
-            drives.selected.write(releases.variant)
+
+        if (!drives.length) {
+            selectedPage = Units.Page.DownloadPage
+            return;
+        }
+
+        // Better check for > 33GB as the device size is not exactly 32GB for "32GB" USB drive
+        if (drives.selected.size > 33000000000) {
+            deviceWarningDialog.show();
+            return
         }
+
+        selectedPage = Units.Page.DownloadPage
+        drives.selected.setImage(releases.variant)
+        drives.selected.write(releases.variant)
     }
 }

src/app/qml/main.qml

@@ -164,5 +164,9 @@ ApplicationWindow {
     CancelDialog {
         id: cancelDialog
     }
+
+    DeviceWarningDialog {
+        id: deviceWarningDialog
+    }
 }