Merge pull request #2841 from janezd/canvas-zoom

[ENH] Canvas: Add zoom

Orange/canvas/application/canvasmain.py

@@ -292,10 +292,9 @@ def setup_ui(self):
 
         tool_actions = self.current_document().toolbarActions()
 
-        (self.canvas_zoom_action, self.canvas_align_to_grid_action,
+        (self.canvas_align_to_grid_action,
          self.canvas_text_action, self.canvas_arrow_action,) = tool_actions
 
-        self.canvas_zoom_action.setIcon(canvas_icons("Search.svg"))
         self.canvas_align_to_grid_action.setIcon(canvas_icons("Grid.svg"))
         self.canvas_text_action.setIcon(canvas_icons("Text Size.svg"))
         self.canvas_arrow_action.setIcon(canvas_icons("Arrow.svg"))
@@ -536,6 +535,21 @@ def setup_actions(self):
                     shortcut=QKeySequence(Qt.ShiftModifier | Qt.Key_R)
                     )
 
+        self.zoom_in_action = \
+            QAction(self.tr("Zoom in"), self,
+                    triggered=self.zoom_in,
+                    shortcut=QKeySequence(Qt.ControlModifier | Qt.Key_Plus))
+
+        self.zoom_out_action = \
+            QAction(self.tr("Zoom out"), self,
+                    triggered=self.zoom_out,
+                    shortcut=QKeySequence(Qt.ControlModifier | Qt.Key_Minus))
+
+        self.zoom_reset_action = \
+            QAction(self.tr("Reset Zoom"), self,
+                    triggered=self.zoom_reset,
+                    shortcut=QKeySequence(Qt.ControlModifier | Qt.Key_0))
+
         if sys.platform == "darwin":
             # Actions for native Mac OSX look and feel.
             self.minimize_action = \
@@ -650,6 +664,12 @@ def setup_menu(self):
         self.view_menu.addAction(self.show_report_action)
 
         self.view_menu.addSeparator()
+        self.view_menu.addAction(self.zoom_in_action)
+        self.view_menu.addAction(self.zoom_out_action)
+        self.view_menu.addAction(self.zoom_reset_action)
+
+        self.view_menu.addSeparator()
+
         self.view_menu.addAction(self.toogle_margins_action)
         menu_bar.addMenu(self.view_menu)
 
@@ -1894,6 +1914,15 @@ def changeEvent(self, event):
 
             QMainWindow.changeEvent(self, event)
 
+    def zoom_in(self):
+        self.scheme_widget.view().change_zoom(1)
+
+    def zoom_out(self):
+        self.scheme_widget.view().change_zoom(-1)
+
+    def zoom_reset(self):
+        self.scheme_widget.view().reset_zoom()
+
     def sizeHint(self):
         """
         Reimplemented from QMainWindow.sizeHint

Orange/canvas/canvas/view.py

@@ -2,10 +2,11 @@
 Canvas Graphics View
 """
 import logging
+from math import copysign
 
 from AnyQt.QtWidgets import QGraphicsView
-from AnyQt.QtGui import QCursor, QIcon
-from AnyQt.QtCore import Qt, QRect, QSize, QRectF, QPoint, QTimer
+from AnyQt.QtGui import QCursor, QIcon, QTransform, QWheelEvent
+from AnyQt.QtCore import QT_VERSION, Qt, QRect, QSize, QRectF, QPoint, QTimer
 
 log = logging.getLogger(__name__)
 
@@ -25,6 +26,8 @@ def __init__(self, *args):
         self.__autoScrollTimer = QTimer(self)
         self.__autoScrollTimer.timeout.connect(self.__autoScrollAdvance)
 
+        self.__scale = 10
+
     def setScene(self, scene):
         QGraphicsView.setScene(self, scene)
         self._ensureSceneRect(scene)
@@ -63,6 +66,33 @@ def mouseReleaseEvent(self, event):
 
         return QGraphicsView.mouseReleaseEvent(self, event)
 
+    def reset_zoom(self):
+        self.__set_zoom(10)
+
+    def change_zoom(self, delta):
+        self.__set_zoom(self.__scale + delta)
+
+    def __set_zoom(self, scale):
+        self.__scale = min(15, max(scale, 3))
+        transform = QTransform()
+        transform.scale(self.__scale / 10, self.__scale / 10)
+        self.setTransform(transform)
+
+    def wheelEvent(self, event: QWheelEvent):
+        # use mouse position as anchor while zooming
+        self.setTransformationAnchor(2)
+        if event.modifiers() & Qt.ControlModifier \
+                and event.buttons() == Qt.NoButton:
+            delta = event.angleDelta().y()
+            if QT_VERSION >= 0x050500 \
+                    and event.source() != Qt.MouseEventNotSynthesized \
+                    and abs(delta) < 50:
+                self.change_zoom(delta / 10)
+            else:
+                self.change_zoom(copysign(1, delta))
+        else:
+            super().wheelEvent(event)
+
     def __shouldAutoScroll(self, pos):
         if self.__autoScroll:
             margin = self.__autoScrollMargin

Orange/canvas/document/schemeedit.py

@@ -171,16 +171,6 @@ def __init__(self, parent=None, ):
         self.__linkMenu.addAction(self.__linkResetAction)
 
     def __setupActions(self):
-
-        self.__zoomAction = \
-            QAction(self.tr("Zoom"), self,
-                    objectName="zoom-action",
-                    checkable=True,
-                    shortcut=QKeySequence.ZoomIn,
-                    toolTip=self.tr("Zoom in the workflow."),
-                    toggled=self.toggleZoom,
-                    )
-
         self.__cleanUpAction = \
             QAction(self.tr("Clean Up"), self,
                     objectName="cleanup-action",
@@ -467,14 +457,12 @@ def toolbarActions(self):
         Return a list of actions that can be inserted into a toolbar.
         At the moment these are:
 
-            - 'Zoom' action
             - 'Clean up' action (align to grid)
             - 'New text annotation' action (with a size menu)
             - 'New arrow annotation' action (with a color menu)
 
         """
-        return [self.__zoomAction,
-                self.__cleanUpAction,
+        return [self.__cleanUpAction,
                 self.__newTextAnnotationAction,
                 self.__newArrowAnnotationAction]
 
@@ -867,18 +855,6 @@ def selectAll(self):
             if item.flags() & QGraphicsItem.ItemIsSelectable:
                 item.setSelected(True)
 
-    def toggleZoom(self, zoom):
-        """
-        Toggle view zoom. If `zoom` is True the scheme is displayed
-        scaled to 150%.
-
-        """
-        view = self.view()
-        if zoom:
-            view.scale(1.5, 1.5)
-        else:
-            view.resetTransform()
-
     def alignToGrid(self):
         """
         Align nodes to a grid.