Initial commit

app/waveform.py

@@ -0,0 +1,123 @@
+"""Waveform display: envelope, playhead, click-to-seek, drag-to-select (trim region)."""
+import numpy as np
+from PySide6.QtCore import QPointF, QRectF, Qt, QTimer, Signal
+from PySide6.QtGui import QColor, QPainter, QPalette, QPen
+from PySide6.QtWidgets import QSizePolicy, QWidget
+
+from . import spinner
+
+
+class Waveform(QWidget):
+    seekRequested = Signal(float)              # seconds
+    selectionChanged = Signal(float, float)    # seconds (start, end); (0, 0) = none
+
+    def __init__(self, parent=None, selectable=False):
+        super().__init__(parent)
+        self.setMinimumHeight(70)
+        self.setSizePolicy(QSizePolicy.Policy.Expanding, QSizePolicy.Policy.Preferred)
+        self.selectable = selectable
+        self.env = None          # (mins, maxs) at a fixed resolution
+        self.duration = 0.0
+        self.playhead = None
+        self.sel = None
+        self._drag = None
+        self.placeholder = "no audio"
+        self.accent = None
+        self.bg = None            # background colour (theme), else the palette's Base
+        self.busy = False         # spinner beside the placeholder (audio being loaded)
+        self._angle = 0
+        self._timer = QTimer(self)
+        self._timer.setInterval(spinner.STEP_MS)
+        self._timer.timeout.connect(self._spin)
+
+    def _spin(self):
+        self._angle = (self._angle + spinner.STEP_DEG) % 360
+        self.update()
+
+    def set_audio(self, x, rate, placeholder="no audio", busy=False):
+        self.placeholder = placeholder
+        self.busy = busy and (x is None or len(x) == 0)
+        self._timer.start() if self.busy else self._timer.stop()
+        self.sel = None
+        self.playhead = None
+        if x is None or len(x) == 0:
+            self.env, self.duration = None, 0.0
+        else:
+            m = x.mean(axis=1) if x.ndim == 2 else x
+            cols = 2000
+            n = len(m)
+            edges = np.linspace(0, n, cols + 1).astype(int)
+            mins = np.array([m[a:b].min() if b > a else 0 for a, b in zip(edges[:-1], edges[1:])])
+            maxs = np.array([m[a:b].max() if b > a else 0 for a, b in zip(edges[:-1], edges[1:])])
+            self.env = (mins, maxs)
+            self.duration = n / float(rate)
+        self.update()
+
+    def set_playhead(self, seconds):
+        self.playhead = seconds
+        self.update()
+
+    def set_selection(self, a, b):
+        self.sel = (min(a, b), max(a, b)) if b != a else None
+        self.update()
+
+    def _x2t(self, x):
+        return max(0.0, min(self.duration, x / max(1, self.width()) * self.duration))
+
+    def _t2x(self, t):
+        return t / self.duration * self.width() if self.duration else 0
+
+    def mousePressEvent(self, e):
+        if not self.duration:
+            return
+        t = self._x2t(e.position().x())
+        if self.selectable and e.button() == Qt.MouseButton.LeftButton and e.modifiers() & Qt.KeyboardModifier.ShiftModifier:
+            self._drag = t
+        elif self.selectable and e.button() == Qt.MouseButton.RightButton:
+            self._drag = t
+        else:
+            self.seekRequested.emit(t)
+
+    def mouseMoveEvent(self, e):
+        if self._drag is not None:
+            self.set_selection(self._drag, self._x2t(e.position().x()))
+
+    def mouseReleaseEvent(self, e):
+        if self._drag is not None:
+            self._drag = None
+            a, b = self.sel if self.sel else (0.0, 0.0)
+            self.selectionChanged.emit(a, b)
+
+    def paintEvent(self, _):
+        p = QPainter(self)
+        pal = self.palette()
+        r = self.rect()
+        p.fillRect(r, self.bg or pal.color(QPalette.ColorRole.Base))
+        mid = r.height() / 2
+        fg = self.accent or pal.color(QPalette.ColorRole.Highlight)
+        if self.env is None:
+            p.setPen(pal.color(QPalette.ColorRole.PlaceholderText))
+            p.drawText(r, Qt.AlignmentFlag.AlignCenter, self.placeholder)
+            if self.busy:
+                tw = p.fontMetrics().horizontalAdvance(self.placeholder)
+                d = 14
+                spinner.paint_arc(p, QRectF(r.center().x() - tw / 2 - d - 8, mid - d / 2, d, d), self._angle)
+            return
+        if self.sel:
+            sc = QColor(fg)
+            sc.setAlpha(50)
+            p.fillRect(QRectF(self._t2x(self.sel[0]), 0, self._t2x(self.sel[1]) - self._t2x(self.sel[0]), r.height()), sc)
+        mins, maxs = self.env
+        w = max(1, r.width())
+        idx = (np.arange(w) * len(mins) / w).astype(int)
+        p.setPen(QPen(fg, 1))
+        for x, i in enumerate(idx):
+            j = min(len(mins), int((x + 1) * len(mins) / w) + 1)
+            lo, hi = mins[i:j].min(), maxs[i:j].max()
+            p.drawLine(QPointF(x, mid - hi * (mid - 2)), QPointF(x, mid - lo * (mid - 2)))
+        p.setPen(QPen(pal.color(QPalette.ColorRole.Mid), 1))
+        p.drawLine(0, int(mid), w, int(mid))
+        if self.playhead is not None:
+            p.setPen(QPen(pal.color(QPalette.ColorRole.Text), 1))
+            x = self._t2x(self.playhead)
+            p.drawLine(QPointF(x, 0), QPointF(x, r.height()))