feat: add subtitle track selection, secondary subtitle and delay

src/qml/PlayerPage.qml

@@ -65,6 +65,27 @@ Kirigami.Page {
         sequence: "Right"
         onActivated: mpv.seek(mpv.position + 5)
     }
+    // Same keys as mpv: z shows subtitles earlier, x later.
+    Shortcut {
+        sequence: "Z"
+        enabled: mpv.fileLoaded
+        onActivated: page.nudgeSubtitleDelay(-0.1)
+    }
+    Shortcut {
+        sequence: "X"
+        enabled: mpv.fileLoaded
+        onActivated: page.nudgeSubtitleDelay(0.1)
+    }
+
+    function nudgeSubtitleDelay(seconds: real) {
+        const delay = mpv.subtitleDelay + seconds
+        mpv.subtitleDelay = delay
+        mpv.showText(KI18n.i18nc("@info:osd", "Subtitle delay: %1 ms", Math.round(delay * 1000)))
+    }
+
+    function isSubtitleFile(url: url): bool {
+        return /\.(srt|ass|ssa|vtt|sub|sup)$/i.test(url.toString())
+    }
 
     FileDialog {
         id: fileDialog
@@ -111,8 +132,14 @@ Kirigami.Page {
             DropArea {
                 anchors.fill: parent
                 onDropped: drop => {
-                    if (drop.hasUrls) {
-                        mpv.loadFile(drop.urls[0])
+                    if (!drop.hasUrls) {
+                        return
+                    }
+                    const url = drop.urls[0]
+                    if (mpv.fileLoaded && page.isSubtitleFile(url)) {
+                        mpv.addSubtitleFile(url)
+                    } else {
+                        mpv.loadFile(url)
                     }
                 }
             }
@@ -165,6 +192,30 @@ Kirigami.Page {
                     text: page.formatTime(mpv.duration)
                     font.features: { "tnum": 1 }
                 }
+
+                QQC2.ToolButton {
+                    id: subtitleButton
+                    enabled: mpv.fileLoaded
+                    focusPolicy: Qt.NoFocus
+                    checkable: true
+                    checked: subtitlePopup.visible
+                    icon.name: "media-view-subtitles-symbolic"
+                    text: KI18n.i18nc("@action:button", "Subtitles")
+                    display: QQC2.AbstractButton.IconOnly
+                    onClicked: subtitlePopup.visible ? subtitlePopup.close() : subtitlePopup.open()
+
+                    QQC2.ToolTip.text: text
+                    QQC2.ToolTip.visible: hovered && !subtitlePopup.visible
+                    QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
+
+                    SubtitlePopup {
+                        id: subtitlePopup
+                        objectName: "subtitlePopup"
+                        mpv: mpv
+                        x: subtitleButton.width - width
+                        y: -height - Kirigami.Units.smallSpacing
+                    }
+                }
             }
         }
     }

src/qml/SubtitlePopup.qml

@@ -0,0 +1,116 @@
+import QtQuick
+import QtQuick.Controls as QQC2
+import QtQuick.Dialogs
+import QtQuick.Layouts
+import org.kde.kirigami as Kirigami
+import org.kde.ki18n
+
+QQC2.Popup {
+    id: popup
+
+    required property MpvItem mpv
+
+    // [{ id, text }] with "Off" first, shared by both track pickers.
+    readonly property var trackModel: [{ id: 0, text: KI18n.i18nc("@item:inlistbox no subtitle", "Off") }]
+        .concat(mpv.subtitleTracks.map(track => ({ id: track.id, text: trackLabel(track) })))
+
+    function trackLabel(track: var): string {
+        const name = track.title || (track.external ? track.externalFilename.split("/").pop() : "")
+        const lang = track.lang ? `[${track.lang}]` : ""
+        const description = [name, lang].filter(part => part.length > 0).join(" ")
+        return KI18n.i18nc("@item:inlistbox subtitle track number and description", "%1: %2",
+                           track.id, description || KI18n.i18nc("@item:inlistbox", "Untitled"))
+    }
+
+    function indexOfTrack(id: int): int {
+        return Math.max(0, trackModel.findIndex(entry => entry.id === id))
+    }
+
+    padding: Kirigami.Units.largeSpacing
+
+    contentItem: Kirigami.FormLayout {
+        QQC2.ComboBox {
+            id: primaryCombo
+            Kirigami.FormData.label: KI18n.i18nc("@label:listbox", "Subtitle:")
+            Layout.preferredWidth: Kirigami.Units.gridUnit * 16
+            model: popup.trackModel
+            textRole: "text"
+            valueRole: "id"
+            onActivated: popup.mpv.subtitleId = currentValue
+
+            // Always reflect what mpv actually selected, also after the user picks an entry.
+            Binding on currentIndex {
+                value: popup.indexOfTrack(popup.mpv.subtitleId)
+                restoreMode: Binding.RestoreNone
+            }
+        }
+
+        QQC2.ComboBox {
+            id: secondaryCombo
+            Kirigami.FormData.label: KI18n.i18nc("@label:listbox", "Secondary subtitle:")
+            Layout.preferredWidth: Kirigami.Units.gridUnit * 16
+            model: popup.trackModel
+            textRole: "text"
+            valueRole: "id"
+            onActivated: popup.mpv.secondarySubtitleId = currentValue
+
+            Binding on currentIndex {
+                value: popup.indexOfTrack(popup.mpv.secondarySubtitleId)
+                restoreMode: Binding.RestoreNone
+            }
+        }
+
+        RowLayout {
+            Kirigami.FormData.label: KI18n.i18nc("@label:spinbox", "Delay:")
+            spacing: Kirigami.Units.smallSpacing
+
+            QQC2.SpinBox {
+                id: delaySpin
+                from: -600000
+                to: 600000
+                stepSize: 100
+                editable: true
+                textFromValue: (value, locale) => KI18n.i18nc("@item:valuesuffix milliseconds", "%1 ms", value)
+                valueFromText: (text, locale) => parseInt(text) || 0
+                onValueModified: popup.mpv.subtitleDelay = value / 1000
+
+                Binding on value {
+                    value: Math.round(popup.mpv.subtitleDelay * 1000)
+                    restoreMode: Binding.RestoreNone
+                }
+            }
+
+            QQC2.ToolButton {
+                enabled: popup.mpv.subtitleDelay !== 0
+                icon.name: "edit-undo"
+                text: KI18n.i18nc("@action:button", "Reset delay")
+                display: QQC2.AbstractButton.IconOnly
+                onClicked: popup.mpv.subtitleDelay = 0
+
+                QQC2.ToolTip.text: text
+                QQC2.ToolTip.visible: hovered
+                QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
+            }
+        }
+
+        QQC2.Button {
+            icon.name: "add-subtitle"
+            text: KI18n.i18nc("@action:button", "Load Subtitle File…")
+            onClicked: subtitleDialog.open()
+        }
+    }
+
+    FileDialog {
+        id: subtitleDialog
+        title: KI18n.i18nc("@title:window", "Load Subtitle")
+        currentFolder: {
+            const url = popup.mpv.currentUrl.toString()
+            return url.substring(0, url.lastIndexOf("/"))
+        }
+        nameFilters: [
+            KI18n.i18nc("@item:inlistbox file filter", "Subtitle files (*.srt *.ass *.ssa *.vtt *.sub *.sup)"),
+            KI18n.i18nc("@item:inlistbox file filter", "All files (*)")
+        ]
+        onAccepted: popup.mpv.addSubtitleFile(selectedFile)
+    }
+}