Copy image to clipboard (#176)

Co-authored-by: Paul Romano <paul.k.romano@gmail.com>

Author: pshriwise

openmc_plotter/main_window.py

@@ -175,6 +175,12 @@ def createMenuBar(self):
         save_image_connector = partial(self.saveImage, filename=None)
         self.saveImageAction.triggered.connect(save_image_connector)
 
+        self.copyImageAction = QAction("&Copy Image", self)
+        self.copyImageAction.setShortcut("Ctrl+Shift+C")
+        self.copyImageAction.setToolTip('Copy plot image to clipboard')
+        self.copyImageAction.setStatusTip('Copy plot image to clipboard')
+        self.copyImageAction.triggered.connect(self.copyImageToClipboard)
+
         self.saveViewAction = QAction("Save &View...", self)
         self.saveViewAction.setShortcut(QtGui.QKeySequence.Save)
         self.saveViewAction.setStatusTip('Save current view settings')
@@ -202,6 +208,7 @@ def createMenuBar(self):
 
         self.fileMenu = self.mainMenu.addMenu('&File')
         self.fileMenu.addAction(self.reloadModelAction)
+        self.fileMenu.addAction(self.copyImageAction)
         self.fileMenu.addAction(self.saveImageAction)
         self.fileMenu.addAction(self.exportDataAction)
         self.fileMenu.addSeparator()
@@ -522,6 +529,14 @@ def saveImage(self, filename=None):
             self.plotIm.saveImage(filename)
             self.statusBar().showMessage('Plot Image Saved', 5000)
 
+    def copyImageToClipboard(self):
+        if self.plotIm.copyImageToClipboard():
+            self.statusBar().showMessage('Plot Image Copied', 5000)
+            return True
+
+        self.statusBar().showMessage('No Plot Image Available', 5000)
+        return False
+
     def saveView(self):
         filename, ext = QFileDialog.getSaveFileName(self,
                                                     "Save View Settings",

openmc_plotter/plotgui.py

@@ -1,3 +1,4 @@
+import io
 from functools import partial
 
 from PySide6 import QtCore, QtGui
@@ -180,6 +181,60 @@ def saveImage(self, filename):
             filename += ".png"
         self.figure.savefig(filename, transparent=True)
 
+    def copyImageToClipboard(self):
+        """Copy the current canvas image to the clipboard."""
+        image = self._export_plot_image()
+        if image is None:
+            return False
+
+        clipboard = QtGui.QGuiApplication.clipboard()
+        if clipboard is None:
+            return False
+
+        clipboard.setImage(image)
+        return True
+
+    def _export_plot_image(self):
+        self.draw()
+        width, height = self.get_width_height()
+        if width <= 0 or height <= 0:
+            return None
+
+        buffer = io.BytesIO()
+        self.figure.savefig(buffer, format='png', transparent=True)
+        image = QtGui.QImage.fromData(buffer.getvalue(), 'PNG')
+        if image.isNull():
+            return None
+
+        crop_rect = self._visible_canvas_rect(image.width(), image.height())
+        if crop_rect.isEmpty():
+            return None
+
+        return image.copy(crop_rect)
+
+    def _visible_canvas_rect(self, image_width, image_height):
+        if self.width() <= 0 or self.height() <= 0:
+            return QtCore.QRect()
+
+        if self.parent is None or not hasattr(self.parent, 'viewport'):
+            return QtCore.QRect(0, 0, image_width, image_height)
+
+        viewport = self.parent.viewport()
+        visible_width = min(viewport.width(), self.width())
+        visible_height = min(viewport.height(), self.height())
+        x_offset = self.parent.horizontalScrollBar().value()
+        y_offset = self.parent.verticalScrollBar().value()
+
+        scale_x = image_width / self.width()
+        scale_y = image_height / self.height()
+
+        return QtCore.QRect(round(x_offset * scale_x),
+                            round(y_offset * scale_y),
+                            round(visible_width * scale_x),
+                            round(visible_height * scale_y)).intersected(
+                                QtCore.QRect(0, 0, image_width, image_height)
+                            )
+
     def getDataIndices(self, event):
         cv = self.model.currentView
 
@@ -506,6 +561,7 @@ def contextMenuEvent(self, event):
                     olapColorAction.triggered.connect(connector)
 
         self.menu.addSeparator()
+        self.menu.addAction(self.main_window.copyImageAction)
         self.menu.addAction(self.main_window.saveImageAction)
         self.menu.addAction(self.main_window.saveViewAction)
         self.menu.addAction(self.main_window.openAction)

tests/setup_test/test.py

@@ -2,6 +2,7 @@
 import shutil
 
 import pytest
+from PySide6 import QtGui, QtWidgets
 
 from openmc_plotter.main_window import MainWindow, _openmcReload
 
@@ -56,3 +57,56 @@ def test_batch_image(tmpdir, qtbot):
     filecmp.cmp(orig / 'ref1.png', tmpdir / 'test1.png')
 
     mw.close()
+
+def test_copy_image_to_clipboard(tmpdir, monkeypatch, qtbot):
+    orig = tmpdir.chdir()
+    QtWidgets.QApplication.instance() or QtWidgets.QApplication([])
+    mw = MainWindow(model_path=orig)
+    _openmcReload(model_path=orig)
+    mw.loadGui()
+    qtbot.addWidget(mw)
+    mw.show()
+
+    class FakeClipboard:
+        def __init__(self):
+            self.image = None
+
+        def setImage(self, image):
+            self.image = image
+
+    fake_clipboard = FakeClipboard()
+    monkeypatch.setattr(QtGui.QGuiApplication,
+                        'clipboard',
+                        staticmethod(lambda: fake_clipboard))
+
+    try:
+        assert mw.waitForPlotIdle(60000)
+        mw.model.currentView.domainVisible = False
+        mw.plotIm.updatePixmap()
+        assert mw.copyImageToClipboard()
+    finally:
+        orig.chdir()
+
+    assert fake_clipboard.image is not None
+    assert not fake_clipboard.image.isNull()
+    assert fake_clipboard.image.hasAlphaChannel()
+
+    canvas_width, canvas_height = mw.plotIm.get_width_height()
+    expected_width = round(
+        min(mw.frame.viewport().width(), mw.plotIm.width())
+        * canvas_width
+        / mw.plotIm.width()
+    )
+    expected_height = round(
+        min(mw.frame.viewport().height(), mw.plotIm.height())
+        * canvas_height
+        / mw.plotIm.height()
+    )
+    assert fake_clipboard.image.width() == pytest.approx(expected_width, abs=1)
+    assert fake_clipboard.image.height() == pytest.approx(expected_height, abs=1)
+
+    center = fake_clipboard.image.pixelColor(fake_clipboard.image.width() // 2,
+                                             fake_clipboard.image.height() // 2)
+    assert center.alpha() == 0
+
+    mw.close()

tests/test_plotgui_clipboard.py

@@ -0,0 +1,80 @@
+from types import SimpleNamespace
+
+import numpy as np
+import pytest
+from PySide6 import QtGui, QtWidgets
+
+from openmc_plotter.plotgui import PlotImage
+
+
+class FakeClipboard:
+
+    def __init__(self):
+        self.image = None
+
+    def setImage(self, image):
+        self.image = image
+
+
+@pytest.fixture
+def qapp():
+    return QtWidgets.QApplication.instance() or QtWidgets.QApplication([])
+
+
+def test_copy_image_to_clipboard_crops_to_plot_and_preserves_alpha(
+    qapp, monkeypatch
+):
+    scroll = QtWidgets.QScrollArea()
+    scroll.resize(220, 160)
+    main_window = SimpleNamespace(
+        logicalDpiX=lambda: 100,
+        zoom=100,
+        coord_label=SimpleNamespace(show=lambda: None, hide=lambda: None),
+        statusBar=lambda: SimpleNamespace(showMessage=lambda *args, **kwargs: None),
+    )
+    plot = PlotImage(model=None, parent=scroll, main_window=main_window)
+    scroll.setWidget(plot)
+    plot.resize(400, 300)
+    plot.figure.clear()
+    plot.ax = plot.figure.subplots()
+    plot.ax.imshow(np.zeros((10, 10, 4)))
+    scroll.show()
+    qapp.processEvents()
+    scroll.horizontalScrollBar().setValue(40)
+    scroll.verticalScrollBar().setValue(30)
+    qapp.processEvents()
+
+    fake_clipboard = FakeClipboard()
+    monkeypatch.setattr(
+        QtGui.QGuiApplication,
+        "clipboard",
+        staticmethod(lambda: fake_clipboard),
+    )
+
+    try:
+        assert plot.copyImageToClipboard()
+    finally:
+        plot.close()
+        scroll.close()
+
+    assert fake_clipboard.image is not None
+    assert not fake_clipboard.image.isNull()
+    assert fake_clipboard.image.hasAlphaChannel()
+
+    canvas_width, canvas_height = plot.get_width_height()
+    expected_width = round(
+        min(scroll.viewport().width(), plot.width()) * canvas_width / plot.width()
+    )
+    expected_height = round(
+        min(scroll.viewport().height(), plot.height()) * canvas_height / plot.height()
+    )
+    assert fake_clipboard.image.width() == pytest.approx(expected_width, abs=1)
+    assert fake_clipboard.image.height() == pytest.approx(expected_height, abs=1)
+    assert fake_clipboard.image.width() < canvas_width
+    assert fake_clipboard.image.height() < canvas_height
+
+    center = fake_clipboard.image.pixelColor(
+        fake_clipboard.image.width() // 2,
+        fake_clipboard.image.height() // 2,
+    )
+    assert center.alpha() == 0