feat: shift key enables size/angle snapping

With SHIFT key:
 - Rectangles become squares
 - Lines snap to 15deg
 - Points snap to integer coordinates

gmc/__init__.py

@@ -1 +1 @@
-__version__ = "1.5.3"
+__version__ = "1.5.4"

gmc/markup_objects/line.py

@@ -2,7 +2,7 @@
 
 from ..views.image_view import ImageView
 from ..settings import settings
-from .polygon import MarkupPolygon, UndoPolygonCreate
+from .polygon import MarkupPolygon, EditableMarkupPolygon, UndoPolygonCreate
 
 Qt = QtCore.Qt
 
@@ -52,11 +52,7 @@ def mouse_press(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
         view.scene().addItem(self)
         return True
 
-    def mouse_move(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
-        self._polygon[1] = view.mapToScene(event.pos())
-        self.update()
-        self.on_change_polygon(self._polygon)
-        return True
+    mouse_move = EditableMarkupPolygon.mouse_move
 
     def mouse_release(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
         self.mouse_move(event, view)
@@ -73,7 +69,4 @@ def mouse_release(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
             view.set_mouse_press(self.prevent_event)
         return True
 
-    def cancel(self, view: ImageView):
-        view.unset_all_events()
-        view.scene().removeItem(self)
-        view.set_mouse_press(self.mouse_press)  # start over
+    cancel = EditableMarkupPolygon.cancel

gmc/markup_objects/point.py

@@ -70,9 +70,11 @@ def on_change_point(self, _):
         pass  # for overriding
 
     def mouse_press(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
-        self._create_pos = view.mapToScene(event.pos())
+        pos = view.mapToScene(event.pos())
+        if QtGui.QGuiApplication.keyboardModifiers() == Qt.Modifier.SHIFT:
+            pos = QPointF(round(pos.x(), round(pos.y())))
         scene = view.scene()
-        scene.undo_stack.push(UndoPointCreate(scene, self, self._create_pos))
+        scene.undo_stack.push(UndoPointCreate(scene, self, pos))
         view.set_mouse_move(self.mouse_move)
         view.set_mouse_release(self.mouse_release)
         view.set_mouse_press(None)

gmc/markup_objects/polygon.py

@@ -4,7 +4,7 @@
 from ..views.image_view import ImageView
 from . import MarkupObjectMeta
 from .moveable_diamond import MoveableDiamond
-from math import hypot
+from math import hypot, atan2, degrees, radians, sin, cos
 from typing import Any, Callable
 from PyQt5.QtCore import Qt, QPointF, QCoreApplication, QRectF
 
@@ -239,7 +239,16 @@ def mouse_doubleclick(
         return True
 
     def mouse_move(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
-        self._polygon[-1] = view.mapToScene(event.pos())
+        pt = view.mapToScene(event.pos())
+        if QtGui.QGuiApplication.keyboardModifiers() == Qt.ShiftModifier:
+            step_deg = 15
+            a: QPointF = self._polygon[-2]
+            dx, dy = pt.x() - a.x(), pt.y() - a.y()
+            angle = degrees(atan2(dx, dy)) + step_deg * 0.5
+            d = hypot(dx, dy)
+            fixed_angle = radians(angle - angle % step_deg)
+            pt = a + QPointF(d * sin(fixed_angle), d * cos(fixed_angle))
+        self._polygon[-1] = pt
         self.update()
         self.on_change_polygon(self._polygon)
         return True

gmc/markup_objects/quadrangle.py

@@ -1,3 +1,4 @@
+from math import copysign
 from PyQt5 import QtGui, QtCore, QtWidgets
 from ..markup_objects.moveable_diamond import MoveableDiamond
 from ..views.image_view import ImageView
@@ -72,14 +73,17 @@ def mouse_move_sequential(
     def mouse_move(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
         p0 = self._polygon.at(0)
         p2 = view.mapToScene(event.pos())
-        polygon = QtGui.QPolygonF(
-            [
-                p0,
-                QtCore.QPointF(p2.x(), p0.y()),
-                p2,
-                QtCore.QPointF(p0.x(), p2.y()),
-            ]
-        )
+        if QtGui.QGuiApplication.keyboardModifiers() != Qt.ShiftModifier:
+            p1 = QtCore.QPointF(p2.x(), p0.y())
+            p3 = QtCore.QPointF(p0.x(), p2.y())
+        else:
+            w, h = p2.x() - p0.x(), p2.y() - p0.y()
+            size = max(abs(w), abs(h))
+            w, h = copysign(size, w), copysign(size, h)
+            p1 = QtCore.QPointF(p0.x() + w, p0.y())
+            p2 = QtCore.QPointF(p0.x() + w, p0.y() + h)
+            p3 = QtCore.QPointF(p0.x(), p0.y() + h)
+        polygon = QtGui.QPolygonF((p0, p1, p2, p3))
         self._polygon = polygon
         self.update()
         self.on_change_polygon(polygon)

gmc/markup_objects/rect.py

@@ -1,4 +1,5 @@
 from typing import Any
+from math import copysign
 from PyQt5 import QtGui, QtWidgets
 from PyQt5.QtCore import Qt, QRectF, QPointF, QSizeF, QElapsedTimer
 
@@ -158,7 +159,16 @@ def mouse_press(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
         return True  # if not 'return True', back objects will be selected
 
     def mouse_move(self, event: QtGui.QMouseEvent, view: ImageView) -> bool:
-        self._rect.setBottomRight(view.mapToScene(event.pos()))
+        if QtGui.QGuiApplication.keyboardModifiers() != Qt.ShiftModifier:
+            self._rect.setBottomRight(view.mapToScene(event.pos()))
+        else:
+            rc = self._rect
+            rc.setBottomRight(view.mapToScene(event.pos()))
+            w, h = rc.width(), rc.height()
+            size = max(abs(w), abs(h))
+            rc.setWidth(copysign(size, w))
+            rc.setHeight(copysign(size, h))
+            self._rect = rc
         self.update()
         self.on_change_rect(self._rect)
         return True

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "run-gmc"
-version = "1.5.3"
+version = "1.5.4"
 authors = [
   { name="Arseniy Terekhin", email="[email protected]" },
 ]