Add first Jupyter backend draft

kiva/jupyter.py

@@ -0,0 +1,100 @@
+"""ipycanvas backend for chaco plot."""
+
+from .basecore2d import GraphicsContextBase
+
+from ipycanvas import Canvas
+
+
+def to_html_color(color):
+    """Turn a list of color values from 0.0 to 1.0 into a valid HTML color."""
+    scaled_color = [int(c * 255) for c in color]
+    if len(scaled_color) == 4:
+        return 'rgba({}, {}, {}, {})'.format(*scaled_color)
+    else:
+        return 'rgb({}, {}, {})'.format(*scaled_color)
+
+
+class KivaGraphicsContext(GraphicsContextBase):
+    """ipycanvas Canvas for Chacoplot."""
+
+    def __init__(self, *args, **kwargs):
+        """Constructor."""
+        super().__init__(*args, **kwargs)
+
+        self.current_fill_color = [0.0, 0.0, 0.0]
+        self.current_stroke_color = [0.0, 0.0, 0.0]
+
+        self.canvas = Canvas()
+
+        # Telling the canvas to not send any draw message before a flush call
+        self.canvas.caching = True
+
+    def flush(self):
+        self.canvas.flush()
+
+    def begin_path(self):
+        super().begin_path()
+        self.canvas.begin_path()
+
+    def move_to(self, x, y):
+        super().move_to(x, y)
+        self.canvas.move_to(x, y)
+
+    def line_to(self, x, y):
+        super().line_to(x, y)
+        self.canvas.line_to(x, y)
+
+    def rect(self, x, y, sx, sy):
+        super().rect(x, y, sx, sy)
+        self.canvas.rect(x, y, sx, sy)
+
+    def close_path(self, tag=None):
+        super().close_path(tag)
+        self.canvas.close_path()
+
+    def curve_to(self, x_ctrl1, y_ctrl1, x_ctrl2, y_ctrl2, x_to, y_to):
+        super().curve_to(x_ctrl1, y_ctrl1, x_ctrl2, y_ctrl2, x_to, y_to)
+        self.canvas.bezier_curve_to(x_ctrl1, y_ctrl1, x_ctrl2, y_ctrl2, x_to, y_to)
+
+    def quad_curve_to(self, x_ctrl, y_ctrl, x_to, y_to):
+        super().quad_curve_to(x_ctrl, y_ctrl, x_to, y_to)
+        self.canvas.quadratic_curve_to(x_ctrl, y_ctrl, x_to, y_to)
+
+    def arc(self, x, y, radius, start_angle, end_angle, cw=False):
+        super().arc(x, y, radius, start_angle, end_angle, cw)
+        self.canvas.quadratic_curve_to(x, y, radius, start_angle, end_angle, not cw)
+
+    def arc_to(self, x1, y1, x2, y2, radius):
+        super().arc_to(x1, y1, x2, y2, radius)
+        self.canvas.arc_to(x1, y1, x2, y2, radius)
+
+    def set_fill_color(self, color):
+        super().set_fill_color(color)
+        self.canvas.fill_style = to_html_color
+        self.current_fill_color = color
+
+    def get_fill_color(self):
+        return self.current_fill_color
+
+    def set_stroke_color(self, color):
+        super().set_stroke_color(color)
+        self.canvas.stroke_style = to_html_color
+        self.current_stroke_color = color
+
+    def get_stroke_color(self):
+        return self.current_stroke_color
+
+    def set_alpha(self, alpha):
+        super().set_alpha(alpha)
+        self.canvas.global_alpha = alpha
+
+    def get_alpha(self, alpha):
+        return self.canvas.global_alpha
+
+    def set_font(self, font):
+        super().set_font(font)
+        self.canvas.font = '{}px {}'.format(font.size, font.face_name)
+
+    def set_font_size(self, size):
+        super().set_font_size(size)
+        self.canvas.font = '{}px {}'.format(self.state.font.size, self.state.font.face_name)