Preview/confirm popup for clipboard pasting

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

@@ -161,8 +161,13 @@ HTextArea {
         }
     }
 
-    onCustomImagePaste: py.callClientCoro(
+    onCustomImagePaste: utils.makePopup(
-        writingUserId, "send_clipboard_image", [chat.roomId, Clipboard.image],
+        "Popups/ConfirmClipboardUploadPopup.qml",
+        {
+            userId: chat.userId,
+            roomId: chat.roomId,
+            roomName: chat.roomInfo.display_name,
+        },
     )
 
     Keys.onEscapePressed: clearReplyTo()

src/gui/Popups/ConfirmClipboardUploadPopup.qml

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+import QtQuick 2.12
+import QtQuick.Controls 2.12
+import QtQuick.Layouts 1.12
+import Clipboard 0.1
+import "../Base"
+import "../Base/Buttons"
+
+HColumnPopup {
+    id: popup
+
+    property string userId
+    property string roomId
+    property string roomName
+
+
+    page.footer: AutoDirectionLayout {
+        ApplyButton {
+            id: uploadButton
+            text: qsTr("Send")
+            icon.name: "confirm-uploading-file"
+            onClicked: {
+                py.callClientCoro(
+                    popup.userId,
+                    "send_clipboard_image",
+                    [popup.roomId, Clipboard.image],
+                )
+                popup.close()
+            }
+        }
+
+        CancelButton {
+            id: cancelButton
+            onClicked: popup.close()
+        }
+    }
+
+    onOpened: uploadButton.forceActiveFocus()
+
+    SummaryLabel {
+        text:
+            qsTr("Send copied image to %1?")
+            .arg(utils.htmlColorize(roomName, theme.colors.accentText))
+
+        textFormat: Text.StyledText
+    }
+
+    HImage {
+        id: image
+
+        property int updateCounter: 0
+
+        source: "image://clipboard/" + updateCounter
+        fillMode: Image.PreserveAspectFit
+
+        Layout.fillWidth: true
+        Layout.fillHeight: true
+        Layout.preferredHeight:  // TODO: loading spinner?
+            status === Image.Ready ?
+            width / (implicitWidth / implicitHeight) :
+            0
+
+        Behavior on Layout.preferredHeight { HNumberAnimation {} }
+
+        Connections {
+            target: Clipboard
+
+            function onContentChanged() {
+                Clipboard.hasImage ? image.updateCounter += 1 : popup.close()
+            }
+        }
+    }
+}