initial support for matplotlib toolwindow

Plots toolwindow is implemented as part of SciView toolwindow.
DataView merged into SciView.

Features:
- open toolwindow with plot on plot available (run/console/rebug)
- plots in toolwindow are in separate tabs with image editor inside
- tabs in toolwindow are closeable
- save plot as file action
- DnD to/from editor supported
- plots toolwindow could be disabled from Settings

python/helpers/pycharm_matplotlib_backend/backend_interagg.py

@@ -0,0 +1,88 @@
+import matplotlib
+import os
+import socket
+import struct
+from matplotlib._pylab_helpers import Gcf
+from matplotlib.backend_bases import FigureManagerBase, ShowBase
+from matplotlib.backends.backend_agg import FigureCanvasAgg
+from matplotlib.figure import Figure
+
+HOST = 'localhost'
+PORT = os.getenv("PYCHARM_MATPLOTLIB_PORT")
+PORT = int(PORT) if PORT is not None else None
+PORT = PORT if PORT != -1 else None
+
+rcParams = matplotlib.rcParams
+verbose = matplotlib.verbose
+
+
+class Show(ShowBase):
+    def __call__(self, **kwargs):
+        managers = Gcf.get_all_fig_managers()
+        if not managers:
+            return
+
+        for manager in managers:
+            manager.show(**kwargs)
+
+    def mainloop(self):
+        pass
+
+
+show = Show()
+
+
+# from pyplot API
+def new_figure_manager(num, *args, **kwargs):
+    FigureClass = kwargs.pop('FigureClass', Figure)
+    figure = FigureClass(*args, **kwargs)
+    return new_figure_manager_given_figure(num, figure)
+
+
+# from pyplot API
+def new_figure_manager_given_figure(num, figure):
+    canvas = FigureCanvasInterAgg(figure)
+    manager = FigureManagerInterAgg(canvas, num)
+    if matplotlib.is_interactive():
+        manager.show()
+    return manager
+
+
+# from pyplot API
+class FigureCanvasInterAgg(FigureCanvasAgg):
+    def __init__(self, figure):
+        FigureCanvasAgg.__init__(self, figure)
+
+    def show(self):
+        FigureCanvasAgg.draw(self)
+        if PORT is None:
+            return
+
+        if matplotlib.__version__ < '1.2':
+            buffer = self.tostring_rgb(0, 0)
+        else:
+            buffer = self.tostring_rgb()
+
+        render = self.get_renderer()
+        width, height = int(render.width), int(render.height) # pass to the socket
+
+        try:
+            sock = socket.socket()
+            sock.connect((HOST, PORT))
+            sock.send(struct.pack('>i', width))
+            sock.send(buffer)
+        except ConnectionRefusedError as _:
+            # nothing bad. It just means, that our tool window doesn't run yet
+            pass
+
+
+class FigureManagerInterAgg(FigureManagerBase):
+    def __init__(self, canvas, num):
+        FigureManagerBase.__init__(self, canvas, num)
+        self.canvas = canvas
+        self._num = num
+        self._shown = False
+
+    def show(self, **kwargs):
+        self.canvas.show()
+        Gcf.destroy(self._num)