python-ase 3.6.0.2515-1.1 / usr / share / pyshared / ase / gui / view.py

#!/usr/bin/env python

# Emacs: treat this as -*- python -*-

import os
import gtk
import tempfile
from math import cos, sin, sqrt, atan
from os.path import basename

import numpy as np

from ase.data.colors import jmol_colors
from ase.gui.repeat import Repeat
from ase.gui.rotate import Rotate
from ase.gui.render import Render
from ase.gui.colors import ColorWindow
from ase.utils import rotate

class View:
    def __init__(self, vbox, rotations):
        self.colormode = 'jmol'  # The default colors
        self.nselected = 0
        self.light_green_markings = 0
        self.axes = rotate(rotations)
        # this is a hack, in order to be able to toggle menu actions off/on
        # without getting into an infinte loop
        self.menu_change = 0
    
        self.atoms_to_rotate = None
        
        self.drawing_area = gtk.DrawingArea()
        self.drawing_area.set_size_request(450, 450)
        self.drawing_area.connect('button_press_event', self.press)
        self.drawing_area.connect('button_release_event', self.release)
        self.drawing_area.connect('motion-notify-event', self.move)
        # Signals used to handle backing pixmap:
        self.drawing_area.connect('expose_event', self.expose_event)
        self.drawing_area.connect('configure_event', self.configure_event)
        self.drawing_area.set_events(gtk.gdk.BUTTON_PRESS_MASK |
                                     gtk.gdk.BUTTON_RELEASE_MASK |
                                     gtk.gdk.BUTTON_MOTION_MASK |
                                     gtk.gdk.POINTER_MOTION_HINT_MASK)
        vbox.pack_start(self.drawing_area)
        self.drawing_area.show()
        self.configured = False
        self.frame = None
        
    def set_coordinates(self, frame=None, focus=None):
        if frame is None:
            frame = self.frame
        self.make_box()
        self.bind(frame)
        n = self.images.natoms
        self.X = np.empty((n + len(self.B1) + len(self.bonds), 3))
        #self.X[n:] = np.dot(self.B1, self.images.A[frame])
        #self.B = np.dot(self.B2, self.images.A[frame])
        self.set_frame(frame, focus=focus, init=True)

    def set_frame(self, frame=None, focus=False, init=False):
        if frame is None:
            frame = self.frame

        n = self.images.natoms

        if self.frame > self.images.nimages:
            self.frame = self.images.nimages - 1
        
        if init or frame != self.frame:
            A = self.images.A
            nc = len(self.B1)
            nb = len(self.bonds)
            
            if init or (A[frame] != A[self.frame]).any():
                self.X[n:n + nc] = np.dot(self.B1, A[frame])
                self.B = np.empty((nc + nb, 3))
                self.B[:nc] = np.dot(self.B2, A[frame])

            if nb > 0:
                P = self.images.P[frame]
                Af = self.images.repeat[:, np.newaxis] * A[frame]
                a = P[self.bonds[:, 0]]
                b = P[self.bonds[:, 1]] + np.dot(self.bonds[:, 2:], Af) - a
                d = (b**2).sum(1)**0.5
                r = 0.65 * self.images.r
                x0 = (r[self.bonds[:, 0]] / d).reshape((-1, 1))
                x1 = (r[self.bonds[:, 1]] / d).reshape((-1, 1))
                self.X[n + nc:] = a + b * x0
                b *= 1.0 - x0 - x1
                b[self.bonds[:, 2:].any(1)] *= 0.5
                self.B[nc:] = self.X[n + nc:] + b

            filenames = self.images.filenames
            filename = filenames[frame]
            if self.frame is None or filename != filenames[self.frame] or filename is None:
                if filename is None:
                    filename = 'ase.gui'
            filename = basename(filename)
            self.window.set_title(filename)

        self.frame = frame
        self.X[:n] = self.images.P[frame]
        self.R = self.X[:n]
        if focus:
            self.focus()
        else:
            self.draw()
        
    def set_colors(self):
        self.colormode = 'jmol'
        self.set_jmol_colors()

    def set_jmol_colors(self):
        self.colors = [None] * (len(jmol_colors) + 1)
        self.colordata = []
        new = self.drawing_area.window.new_gc
        alloc = self.colormap.alloc_color
        for z in self.images.Z:
            if self.colors[z] is None:
                c, p, k = jmol_colors[z]
                self.colors[z] = new(alloc(int(65535 * c),
                                           int(65535 * p),
                                           int(65535 * k)))
        hasfound = {}
        for z in self.images.Z:
            if z not in hasfound:
                hasfound[z] = True
                self.colordata.append([z, jmol_colors[z]])
                
    def plot_cell(self):
        V = self.images.A[0]
        R1 = []
        R2 = []
        for c in range(3):
            v = V[c]
            d = sqrt(np.dot(v, v))
            n = max(2, int(d / 0.3))
            h = v / (2 * n - 1)
            R = np.arange(n)[:, None] * (2 * h)
            for i, j in [(0, 0), (0, 1), (1, 0), (1, 1)]:
                R1.append(R + i * V[(c + 1) % 3] + j * V[(c + 2) % 3])
                R2.append(R1[-1] + h)
        return np.concatenate(R1), np.concatenate(R2)

    def make_box(self):
        if not self.ui.get_widget('/MenuBar/ViewMenu/ShowUnitCell'
                                  ).get_active():
            self.B1 = self.B2 = np.zeros((0, 3))
            return
        
        V = self.images.A[0]
        nn = []
        for c in range(3):
            v = V[c]
            d = sqrt(np.dot(v, v))
            n = max(2, int(d / 0.3))
            nn.append(n)
        self.B1 = np.zeros((2, 2, sum(nn), 3))
        self.B2 = np.zeros((2, 2, sum(nn), 3))
        n1 = 0
        for c, n in enumerate(nn):
            n2 = n1 + n
            h = 1.0 / (2 * n - 1)
            R = np.arange(n) * (2 * h)

            for i, j in [(0, 0), (0, 1), (1, 0), (1, 1)]:
                self.B1[i, j, n1:n2, c] = R
                self.B1[i, j, n1:n2, (c + 1) % 3] = i
                self.B1[i, j, n1:n2, (c + 2) % 3] = j
            self.B2[:, :, n1:n2] = self.B1[:, :, n1:n2]
            self.B2[:, :, n1:n2, c] += h
            n1 = n2
        self.B1.shape = (-1, 3)
        self.B2.shape = (-1, 3)

    def bind(self, frame):
        if not self.ui.get_widget('/MenuBar/ViewMenu/ShowBonds'
                                  ).get_active():
            self.bonds = np.empty((0, 5), int)
            return
        
        from ase.atoms import Atoms
        from ase.calculators.neighborlist import NeighborList
        nl = NeighborList(self.images.r * 1.5, skin=0, self_interaction=False)
        nl.update(Atoms(positions=self.images.P[frame],
                        cell=(self.images.repeat[:, np.newaxis] *
                              self.images.A[frame]),
                        pbc=self.images.pbc))
        nb = nl.nneighbors + nl.npbcneighbors
        self.bonds = np.empty((nb, 5), int)
        if nb == 0:
            return
        
        n1 = 0
        for a in range(self.images.natoms):
            indices, offsets = nl.get_neighbors(a)
            n2 = n1 + len(indices)
            self.bonds[n1:n2, 0] = a
            self.bonds[n1:n2, 1] = indices
            self.bonds[n1:n2, 2:] = offsets
            n1 = n2

        i = self.bonds[:n2, 2:].any(1)
        self.bonds[n2:, 0] = self.bonds[i, 1]
        self.bonds[n2:, 1] = self.bonds[i, 0]
        self.bonds[n2:, 2:] = -self.bonds[i, 2:]

    def toggle_show_unit_cell(self, action):
        self.set_coordinates()
        
    def reset_tools_modes(self):
        dummy = self.menu_change
        self.menu_change = 1
        self.atoms_to_rotate = None
        for c_mode in ['Rotate', 'Orient', 'Move']:
              self.ui.get_widget('/MenuBar/ToolsMenu/%sAtoms' % c_mode).set_active(False)
        self.light_green_markings = 0
        self.menu_change = 0        
        self.draw()
        
                      
    def toggle_mode(self, mode):
        self.menu_change = 1
        i_sum = 0
        for c_mode in ['Rotate', 'Orient', 'Move']:
            i_sum += self.ui.get_widget('/MenuBar/ToolsMenu/%sAtoms' % c_mode).get_active() 
        if i_sum == 0 or (i_sum == 1 and sum(self.images.selected) == 0):
            self.reset_tools_modes()
            return()
            
        if i_sum == 2:
            try:
                self.images.selected = self.atoms_to_rotate_0.copy()
            except:
                self.atoms_to_rotate_0 = self.images.selected.copy()
        if i_sum == 1:
            self.atoms_to_rotate_0 = self.images.selected.copy()

        for c_mode in ['Rotate', 'Orient', 'Move']:
            if c_mode != mode:
                  self.ui.get_widget('/MenuBar/ToolsMenu/%sAtoms' % c_mode).set_active(False) 
        
        if self.ui.get_widget('/MenuBar/ToolsMenu/%sAtoms' % mode).get_active():
            self.atoms_to_rotate_0 = self.images.selected.copy()
            for i in range(len(self.images.selected)):
               self.images.selected[i] = False
            self.light_green_markings = 1
        else:
            try: 
                atr = self.atoms_to_rotate_0
                for i in range(len(self.images.selected)):
                    self.images.selected[i] = atr[i]
            except:
                pass                
                
        self.menu_change = 0
        self.draw()
                      
    def toggle_move_mode(self, action):
        """
        Toggles the move mode, where the selected atoms can be moved with the arrow
        keys and pg up/dn. If the shift key is pressed, the movement will be reduced.
        
        The movement will be relative to the current rotation of the coordinate system.
        
        The implementation of the move mode is found in the gui.scroll
        """
        if not (self.menu_change):
            self.toggle_mode('Move')

    def toggle_rotate_mode(self, action):
        """
        Toggles the rotate mode, where the selected atoms can be rotated with the arrow keys
        and pg up/dn. If the shift key is pressed, the rotation angle will be reduced.
        
        The atoms to be rotated will be marked with light green - and the COM of the selected
        atoms will be used as the COM of the rotation. This can be changed while rotating the
        selected atoms.
        
        If only two atoms are seleceted, and the number of atoms to be rotated is different from
        two, the selected atoms will define the axis of rotation.
        
        The implementation of the rotate mode is found in the gui.scroll
        """
        if not (self.menu_change):
            self.toggle_mode('Rotate')
                
    def toggle_orient_mode(self, action):
        """
        Toggle the orientation mode - the orientation of the atoms will be changed
        according to the arrow keys selected.
        
        If nothing is selected, standard directions are x, y and z
        if two atoms are selected, the standard directions are along their displacement vector
        if three atoms are selected, the orientation is changed according to the normal of these
        three vectors.
        """
        if not (self.menu_change):
            self.toggle_mode('Orient')
        self.orient_normal = np.array([1.0, 0.0, 0.0])
        sel_pos = []
        for i, j in enumerate(self.atoms_to_rotate_0):
            if j: 
                sel_pos.append(self.R[i])
        if len(sel_pos) == 2:
            self.orient_normal = sel_pos[0] - sel_pos[1]
        if len(sel_pos) == 3:
            v1 = sel_pos[1] - sel_pos[0]
            v2 = sel_pos[1] - sel_pos[2]
            self.orient_normal = np.cross(v1, v2)
        self.orient_normal /= sum(self.orient_normal ** 2) ** 0.5
            
    def toggle_show_axes(self, action):
        self.draw()

    def toggle_show_bonds(self, action):
        self.set_coordinates()

    def repeat_window(self, menuitem):
        self.reset_tools_modes()
        Repeat(self)

    def rotate_window(self, menuitem):
        Rotate(self)

    def colors_window(self, menuitem):
        ColorWindow(self)

    def focus(self, x=None):
        if (self.images.natoms == 0 and not
            self.ui.get_widget('/MenuBar/ViewMenu/ShowUnitCell').get_active()):
            self.scale = 1.0
            self.center = np.zeros(3)
            self.draw()
            return
        
        P = np.dot(self.X, self.axes)
        n = self.images.natoms
        P[:n] -= self.images.r[:, None]
        P1 = P.min(0) 
        P[:n] += 2 * self.images.r[:, None]
        P2 = P.max(0)
        self.center = np.dot(self.axes, (P1 + P2) / 2)
        S = 1.3 * (P2 - P1)
        if S[0] * self.height < S[1] * self.width:
            self.scale = self.height / S[1]
        else:
            self.scale = self.width / S[0]
        self.draw()

    def reset_view(self, menuitem):
        self.axes = rotate('0.0x,0.0y,0.0z')
        self.set_coordinates()
        self.focus(self)

    def get_colors(self, rgb = False):
        Z = self.images.Z
        if rgb:
            # create a shape that is equivalent to self.colors,
            # but contains rgb data instead gtk.gdk.GCX11 objects
            colarray = [None] * max(len(jmol_colors)+1,len(self.colordata))
            for z, c in self.colordata:
                colarray[z] = c
        else:
            colarray = self.colors
        if self.colormode == 'jmol' or self.colormode == 'atno':
            colors = np.array(colarray)[Z]
        elif self.colormode == 'tags':
            colors = np.array(colarray)[self.images.T[self.frame]]
        elif self.colormode == 'force':
            F = self.images.F[self.frame]
            F = np.sqrt(((F*self.images.dynamic[:,np.newaxis])**2).sum(axis=-1))  # The absolute force
            nF = (F - self.colormode_force_data[0]) * self.colormode_force_data[1]
            nF = np.clip(nF.astype(int), 0, len(self.colors)-1)
            colors = np.array(colarray)[nF]
        elif self.colormode == 'velocity':
            V = self.images.V[self.frame]
            V = np.sqrt((V*V).sum(axis=-1))  # The absolute velocity
            nV = (V - self.colormode_velocity_data[0]) * self.colormode_velocity_data[1]
            nV = np.clip(nV.astype(int), 0, len(self.colors)-1)
            colors = np.array(colarray)[nV]
        elif self.colormode == 'manual':
            colors = colarray
        elif self.colormode == 'same':
            colors = [colarray[0]] * self.images.natoms
        else:
            raise RuntimeError('Unknown color mode: %s' % (self.colormode,))
        return colors

    def repeat_colors(self, repeat):
        natoms = self.images.natoms
        if self.colormode == 'manual':
            a0 = 0
            colors = self.colors
            colordata = self.colordata
            for i0 in range(repeat[0]):
                for i1 in range(repeat[1]):
                    for i2 in range(repeat[2]):
                        a1 = a0 + natoms
                        colors[a0:a1] = self.colors[:natoms]
                        colordata[a0:a1] = self.colordata[:natoms]
                        a0 = a1
            self.colors = colors
            self.colordata = colordata

    def my_arc(self, gc, fill, j, X, r, n, A):
   
        if self.images.shapes is not None:
            rx = (self.images.shapes[j, 0]).round().astype(int)
            ry = (self.images.shapes[j, 1]).round().astype(int)
            rz = (self.images.shapes[j, 2]).round().astype(int)
            circle = rx == ry and ry == rz
        else:
            circle = True

        if not circle:
            Q = self.images.Q[j]
            X2d = np.array([X[j][0], X[j][1]])
            Ellipsoid = np.array([[1. / (rx*rx), 0, 0],
                                  [0, 1. / (ry*ry), 0],
                                  [0, 0, 1. / (rz*rz)]
                                  ])
            # Ellipsoid rotatet by quaternion as Matrix X' = R X R_transpose
            El_r = np.dot(Q.rotation_matrix(),
                          np.dot(Ellipsoid, 
                                 np.transpose(Q.rotation_matrix())))
            # Ellipsoid rotated by quaternion and axes as 
            # Matrix X' =  R_axes X' R_axes
            El_v = np.dot(np.transpose(self.axes), np.dot(El_r, self.axes))
            # Projection of rotatet ellipsoid on xy plane
            El_p = Ell = np.array([
                    [El_v[0][0] - El_v[0][2] * El_v[0][2] / El_v[2][2],
                     El_v[0][1] - El_v[0][2] * El_v[1][2] / El_v[2][2]],
                    [El_v[0][1] - El_v[0][2] * El_v[1][2] / El_v[2][2],
                     El_v[1][1] - El_v[1][2] * El_v[1][2] / El_v[2][2]]
                    ])
            # diagonal matrix der Ellipse gibt halbachsen
            El_p_diag = np.linalg.eig(El_p)
            # Winkel mit dem Ellipse in xy gedreht ist aus 
            # eigenvektor der diagonal matrix
            phi = atan(El_p_diag[1][0][1] / El_p_diag[1][0][0])
            tupl = []
            alpha = np.array(range(20)) *2* np.pi /20
            El_xy = np.array([sqrt(1. / (El_p_diag[0][0])) *
                              np.cos(alpha)*np.cos(phi) 
                              - sqrt(1./(El_p_diag[0][1])) * 
                              np.sin(alpha) * np.sin(phi),
                              sqrt(1./(El_p_diag[0][0])) * 
                              np.cos(alpha)*np.sin(phi)
                              + sqrt(1./(El_p_diag[0][1])) * 
                              np.sin(alpha) * np.cos(phi)])

            tupl = (El_xy.transpose() * self.scale + 
                    X[j][:2]).round().astype(int)
            # XXX there must be a better way
            tupl = [tuple(i) for i in tupl]

            return self.pixmap.draw_polygon( gc, fill, tupl)
        
        dx = dy = (2 * r).round().astype(int)
        rj = dx[j]
        
        return self.pixmap.draw_arc(gc, fill, A[j, 0], A[j, 1], rj, rj, 
                                    0, 23040)

    def draw(self, status=True):
        self.pixmap.draw_rectangle(self.white_gc, True, 0, 0,
                                   self.width, self.height)
        axes = self.scale * self.axes * (1, -1, 1)
        offset = (np.dot(self.center, axes) -
                  (0.5 * self.width, 0.5 * self.height, 0))
        X = np.dot(self.X, axes) - offset
        n = self.images.natoms
        self.indices = X[:, 2].argsort()
        if self.ui.get_widget('/MenuBar/ViewMenu/ShowBonds').get_active():
            r = self.images.r * (0.65 * self.scale)
        else:
            r = self.images.r * self.scale
        P = self.P = X[:n, :2]
        A = (P - r[:, None]).round().astype(int)
        X1 = X[n:, :2].round().astype(int)
        X2 = (np.dot(self.B, axes) - offset).round().astype(int)
        d = (2 * r).round().astype(int)

        selected_gc = self.selected_gc
        colors = self.get_colors()
        arc = self.pixmap.draw_arc
        line = self.pixmap.draw_line
        black_gc = self.black_gc
        dynamic = self.images.dynamic
        selected = self.images.selected
        visible = self.images.visible
        for a in self.indices:
            if a < n:
                ra = d[a]
                if visible[a]:
                    self.my_arc(colors[a], True, a, X, r, n, A)
                if  self.light_green_markings and self.atoms_to_rotate_0[a]:
                    arc(self.green, False, A[a, 0] + 2, A[a, 1] + 2,
                        ra - 4, ra - 4, 0, 23040)

                if not dynamic[a]:
                    R1 = int(0.14644 * ra)
                    R2 = int(0.85355 * ra)
                    line(black_gc,
                         A[a, 0] + R1, A[a, 1] + R1,
                         A[a, 0] + R2, A[a, 1] + R2)
                    line(black_gc,
                         A[a, 0] + R2, A[a, 1] + R1,
                         A[a, 0] + R1, A[a, 1] + R2)
                if selected[a]:
                    self.my_arc(selected_gc, False, a, X, r, n, A)
                elif visible[a]:
                    self.my_arc(black_gc, False, a, X, r, n, A)
            else:
                a -= n
                line(black_gc, X1[a, 0], X1[a, 1], X2[a, 0], X2[a, 1])

        if self.ui.get_widget('/MenuBar/ViewMenu/ShowAxes').get_active():
            self.draw_axes()

        if self.images.nimages > 1:
            self.draw_frame_number()
            
        self.drawing_area.window.draw_drawable(self.white_gc, self.pixmap,
                                               0, 0, 0, 0,
                                               self.width, self.height)

        if status:
            self.status()

    def draw_axes(self):
        from ase.quaternions import Quaternion
        q = Quaternion().from_matrix(self.axes)
        L = np.zeros((10, 2, 3))
        L[:3, 1] = self.axes * 15
        L[3:5] = self.axes[0] * 20
        L[5:7] = self.axes[1] * 20
        L[7:] = self.axes[2] * 20
        L[3:, :, :2] += (((-4, -5), (4,  5)), ((-4,  5), ( 4, -5)), 
                         ((-4,  5), (0,  0)), ((-4, -5), ( 4,  5)), 
                         ((-4,  5), (4,  5)), (( 4,  5), (-4, -5)), 
                         ((-4, -5), (4, -5)))
        L = L.round().astype(int)
        L[:, :, 0] += 20
        L[:, :, 1] = self.height - 20 - L[:, :, 1]
        line = self.pixmap.draw_line
        colors = ([self.black_gc] * 3 +
                  [self.red] * 2 + [self.green] * 2 + [self.blue] * 3)
        for i in L[:, 1, 2].argsort():
            (a, b), (c, d) = L[i, :, :2]
            line(colors[i], a, b, c, d)

    digits = np.array(((1, 1, 1, 1, 1, 1, 0),
                       (0, 1, 1, 0, 0, 0, 0),
                       (1, 0, 1, 1, 0, 1, 1),
                       (1, 1, 1, 1, 0, 0, 1),
                       (0, 1, 1, 0, 1, 0, 1),
                       (1, 1, 0, 1, 1, 0, 1),
                       (1, 1, 0, 1, 1, 1, 1),
                       (0, 1, 1, 1, 0, 0, 0),
                       (1, 1, 1, 1, 1, 1, 1),
                       (0, 1, 1, 1, 1, 0, 1)), bool)

    bars = np.array(((0, 2, 1, 2),
                     (1, 2, 1, 1),
                     (1, 1, 1, 0),
                     (1, 0, 0, 0),
                     (0, 0, 0, 1),
                     (0, 1, 0, 2),
                     (0, 1, 1, 1))) * 5
    
    def draw_frame_number(self):
        n = str(self.frame)
        x = self.width - 3 - 8 * len(n)
        y = self.height - 27
        color = self.black_gc
        line = self.pixmap.draw_line
        for c in n:
            bars = View.bars[View.digits[int(c)]]
            for a, b, c, d in bars:
                line(color, a + x, b + y, c + x, d + y)
            x += 8
        
    def release(self, drawing_area, event):
        if event.button != 1:
            return

        selected = self.images.selected
        selected_ordered = self.images.selected_ordered

        if event.time < self.t0 + 200:  # 200 ms
            d = self.P - self.xy
            hit = np.less((d**2).sum(1), (self.scale * self.images.r)**2)
            for a in self.indices[::-1]:
                if a < self.images.natoms and hit[a]:
                    if event.state & gtk.gdk.CONTROL_MASK:
                        selected[a] = not selected[a]
                        if selected[a]: 
                            selected_ordered += [a]
                        elif len(selected_ordered) > 0:
                            if selected_ordered[-1] == a:
                                selected_ordered = selected_ordered[:-1]
                            else:
                                selected_ordered = []
                    else:
                        selected[:] = False
                        selected[a] = True
                        selected_ordered = [a]
                    break
            else:
                selected[:] = False
                selected_ordered = []
            self.draw()
        else:
            A = (event.x, event.y)
            C1 = np.minimum(A, self.xy)
            C2 = np.maximum(A, self.xy)
            hit = np.logical_and(self.P > C1, self.P < C2)
            indices = np.compress(hit.prod(1), np.arange(len(hit)))
            if not (event.state & gtk.gdk.CONTROL_MASK):
                selected[:] = False
            selected[indices] = True
            if len(indices) == 1 and indices[0] not in self.images.selected_ordered: 
                selected_ordered += [indices[0]]
            elif len(indices) > 1:
                selected_ordered = []
            self.draw()

        indices = np.arange(self.images.natoms)[self.images.selected]
        if len(indices) != len(selected_ordered):
            selected_ordered = []
        self.images.selected_ordered = selected_ordered

    def press(self, drawing_area, event):
        self.button = event.button
        self.xy = (event.x, event.y)
        self.t0 = event.time
        self.axes0 = self.axes
        self.center0 = self.center
        
    def move(self, drawing_area, event):
             
        x, y, state = event.window.get_pointer()
        x0, y0 = self.xy
        if self.button == 1:
            window = self.drawing_area.window
            window.draw_drawable(self.white_gc, self.pixmap,
                                 0, 0, 0, 0,
                                 self.width, self.height)
            x0 = int(round(x0))
            y0 = int(round(y0))
            window.draw_rectangle(self.selected_gc, False,
                                  min(x, x0), min(y, y0),
                                  abs(x - x0), abs(y - y0))
            return
        if self.button == 2:
            return
        if state & gtk.gdk.SHIFT_MASK:
            self.center = (self.center0 -
                           np.dot(self.axes, (x - x0, y0 - y, 0)) / self.scale)
        else:
            # Snap mode: the a-b angle and t should multipla of 15 degrees ???
            a = x - x0
            b = y0 - y
            t = sqrt(a * a + b * b)
            if t > 0:
                a /= t
                b /= t
            else:
                a = 1.0
                b = 0.0
            c = cos(0.01 * t)
            s = -sin(0.01 * t)
            rotation = np.array([(c * a * a + b * b, (c - 1) * b * a, s * a),
                                 ((c - 1) * a * b, c * b * b + a * a, s * b),
                                 (-s * a, -s * b, c)])
            self.axes = np.dot(self.axes0, rotation)
            if self.images.natoms > 0:
                com = self.X[:self.images.natoms].mean(0) 
            else:
                com = self.images.A[self.frame].mean(0)
            self.center = com - np.dot(com - self.center0,
                                       np.dot(self.axes0, self.axes.T))
        self.draw(status=False)
        
    # Create a new backing pixmap of the appropriate size
    def configure_event(self, drawing_area, event):
        if self.configured:
            w = self.width
            h = self.height
        else:
            self.colormap = self.drawing_area.get_colormap()
            self.black_gc = self.drawing_area.get_style().black_gc
            self.white_gc = self.drawing_area.get_style().white_gc
            self.red = self.drawing_area.window.new_gc(
                self.colormap.alloc_color(62345, 0, 0), line_width=2)
            self.green = self.drawing_area.window.new_gc(
                self.colormap.alloc_color(0, 54456, 0), line_width=2)
            self.blue = self.drawing_area.window.new_gc(
                self.colormap.alloc_color(0, 0, 54456), line_width=2)
            self.selected_gc = self.drawing_area.window.new_gc(
                self.colormap.alloc_color(0, 16456, 0),
                line_width=3)
            
        x, y, self.width, self.height = drawing_area.get_allocation()
        self.pixmap = gtk.gdk.Pixmap(drawing_area.window,
                                     self.width, self.height)
        if self.configured:
            self.scale *= sqrt(1.0 * self.width * self.height / (w * h))
            self.draw()
        self.configured = True
        
    # Redraw the screen from the backing pixmap
    def expose_event(self, drawing_area, event):
        x , y, width, height = event.area
        gc = self.white_gc
        drawing_area.window.draw_drawable(gc, self.pixmap,
                                          x, y, x, y, width, height)

    def external_viewer(self, action):
        name = action.get_name()
        command = {'Avogadro' : 'avogadro',
                   'XMakeMol': 'xmakemol -f',
                   'RasMol':'rasmol -xyz',
                   'VMD': 'vmd'}[name]
        fd, filename = tempfile.mkstemp('.xyz', 'ase.gui-')
        os.close(fd)
        self.images.write(filename)
        os.system('(%s %s &); (sleep 60; rm %s) &' %
                  (command, filename, filename))

    def render_window(self, action):
        Render(self)