Share waveform data and plot navigation and retain processing results

python/set_devices/qt_ports/plot_navigation.py

@@ -0,0 +1,112 @@
+"""Common keyboard and wheel gestures for all plot canvases (Qt 5/6)."""
+try:
+    from PySide6.QtCore import Qt
+    from PySide6.QtWidgets import QScrollArea
+except ImportError:
+    from PySide2.QtCore import Qt
+    from PySide2.QtWidgets import QScrollArea
+
+NAVIGATION_HINT = ('Колесо и +/− — масштаб X; Ctrl + колесо и Ctrl + +/− — масштаб Y. '
+                   'ЛКМ на свободном поле — перемещение; ←/→ — перемещение по X; Home/End — начало/конец.')
+
+
+class PlotNavigation:
+    def setup_navigation(self):
+        self.setFocusPolicy(Qt.StrongFocus)
+        self.setToolTip(NAVIGATION_HINT)
+
+    def keyPressEvent(self, event):
+        key = event.key()
+        modifiers = event.modifiers()
+        if modifiers & (Qt.AltModifier | Qt.MetaModifier):
+            return super().keyPressEvent(event)
+        if key in (Qt.Key_Plus, Qt.Key_Equal, Qt.Key_Minus):
+            self._navigation_zoom(1.25 if key != Qt.Key_Minus else .8,
+                                  bool(modifiers & Qt.ControlModifier))
+        elif key in (Qt.Key_Left, Qt.Key_Right) and not (modifiers & Qt.ControlModifier):
+            self._navigation_pan(-.1 if key == Qt.Key_Left else .1)
+        elif key in (Qt.Key_Home, Qt.Key_End):
+            self._navigation_edge(key == Qt.Key_End)
+        else:
+            return super().keyPressEvent(event)
+        event.accept()
+
+    def wheelEvent(self, event):
+        position = event.position() if hasattr(event, 'position') else event.posF()
+        rect = self.plot_rect() if hasattr(self, 'plot_rect') else self.rect()
+        if not rect.contains(position.toPoint()):
+            event.ignore()
+            return
+        delta = event.angleDelta()
+        ticks = delta.y() or delta.x()
+        if not ticks:
+            pixels = event.pixelDelta()
+            ticks = (pixels.y() or pixels.x()) * 2
+        if ticks:
+            self.setFocus(Qt.MouseFocusReason)
+            self._navigation_zoom(1.25 ** max(-8, min(8, ticks / 120)),
+                                  bool(event.modifiers() & Qt.ControlModifier), position)
+        event.accept()
+
+
+class ScrollPlotNavigation(PlotNavigation):
+    """Canvas navigation for waveforms whose viewport is a QScrollArea."""
+    def scroll_area(self):
+        parent = self.parentWidget()
+        while parent is not None and not isinstance(parent, QScrollArea):
+            parent = parent.parentWidget()
+        return parent
+
+    def _navigation_zoom(self, factor, vertical, position=None):
+        scroll = self.scroll_area()
+        size = self.height() if vertical else self.width()
+        if position is not None:
+            anchor = position.y() if vertical else position.x()
+        elif scroll is not None:
+            bar = scroll.verticalScrollBar() if vertical else scroll.horizontalScrollBar()
+            anchor = bar.value() + bar.pageStep() / 2
+        else:
+            anchor = size / 2
+        self.zoom_dragged.emit('y' if vertical else 'x', factor, anchor / max(1, size))
+
+    def _navigation_pan(self, fraction):
+        scroll = self.scroll_area()
+        if scroll is not None:
+            bar = scroll.horizontalScrollBar()
+            bar.setValue(round(bar.value() + fraction * bar.pageStep()))
+            self.navigation_panned()
+
+    def _navigation_edge(self, end):
+        scroll = self.scroll_area()
+        if scroll is not None:
+            bar = scroll.horizontalScrollBar()
+            bar.setValue(bar.maximum() if end else bar.minimum())
+            self.navigation_panned()
+
+    def navigation_panned(self):
+        pass
+
+    def begin_pan(self, event):
+        self.setFocus(Qt.MouseFocusReason)
+        self._pan_position = event.globalPosition() if hasattr(event, 'globalPosition') else event.globalPos()
+        self.setCursor(Qt.ClosedHandCursor)
+
+    def move_pan(self, event):
+        previous = getattr(self, '_pan_position', None)
+        if previous is None:
+            return
+        position = event.globalPosition() if hasattr(event, 'globalPosition') else event.globalPos()
+        delta = position - previous
+        self._pan_position = position
+        scroll = self.scroll_area()
+        if scroll is not None:
+            for bar, amount in ((scroll.horizontalScrollBar(), delta.x()), (scroll.verticalScrollBar(), delta.y())):
+                bar.setValue(round(bar.value() - amount))
+            if delta.x():
+                self.navigation_panned()
+
+    def end_pan(self, event):
+        self.move_pan(event)
+        self._pan_position = None
+        self.unsetCursor()
+