robot_steering.py

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# Copyright (c) 2011, Dirk Thomas, TU Darmstadt
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
#   * Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#   * Redistributions in binary form must reproduce the above
#     copyright notice, this list of conditions and the following
#     disclaimer in the documentation and/or other materials provided
#     with the distribution.
#   * Neither the name of the TU Darmstadt nor the names of its
#     contributors may be used to endorse or promote products derived
#     from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

from __future__ import division
import os
import rospkg

from geometry_msgs.msg import Twist
import rospy
from python_qt_binding import loadUi
from python_qt_binding.QtCore import Qt, QTimer, Slot
from python_qt_binding.QtGui import QKeySequence
from python_qt_binding.QtWidgets import QShortcut, QWidget
from rqt_gui_py.plugin import Plugin


class RobotSteering(Plugin):

    slider_factor = 1000.0

    def __init__(self, context):
        super(RobotSteering, self).__init__(context)
        self.setObjectName('RobotSteering')

        self._publisher = None

        self._widget = QWidget()
        rp = rospkg.RosPack()
        ui_file = os.path.join(
            rp.get_path('rqt_robot_steering'), 'resource', 'RobotSteering.ui')
        loadUi(ui_file, self._widget)
        self._widget.setObjectName('RobotSteeringUi')
        if context.serial_number() > 1:
            self._widget.setWindowTitle(
                self._widget.windowTitle() + (' (%d)' % context.serial_number()))
        context.add_widget(self._widget)

        self._widget.topic_line_edit.textChanged.connect(
            self._on_topic_changed)
        self._widget.stop_push_button.pressed.connect(self._on_stop_pressed)

        self._widget.x_linear_slider.valueChanged.connect(
            self._on_x_linear_slider_changed)
        self._widget.z_angular_slider.valueChanged.connect(
            self._on_z_angular_slider_changed)

        self._widget.increase_x_linear_push_button.pressed.connect(
            self._on_strong_increase_x_linear_pressed)
        self._widget.reset_x_linear_push_button.pressed.connect(
            self._on_reset_x_linear_pressed)
        self._widget.decrease_x_linear_push_button.pressed.connect(
            self._on_strong_decrease_x_linear_pressed)
        self._widget.increase_z_angular_push_button.pressed.connect(
            self._on_strong_increase_z_angular_pressed)
        self._widget.reset_z_angular_push_button.pressed.connect(
            self._on_reset_z_angular_pressed)
        self._widget.decrease_z_angular_push_button.pressed.connect(
            self._on_strong_decrease_z_angular_pressed)

        self._widget.max_x_linear_double_spin_box.valueChanged.connect(
            self._on_max_x_linear_changed)
        self._widget.min_x_linear_double_spin_box.valueChanged.connect(
            self._on_min_x_linear_changed)
        self._widget.max_z_angular_double_spin_box.valueChanged.connect(
            self._on_max_z_angular_changed)
        self._widget.min_z_angular_double_spin_box.valueChanged.connect(
            self._on_min_z_angular_changed)

        self.shortcut_w = QShortcut(QKeySequence(Qt.Key_W), self._widget)
        self.shortcut_w.setContext(Qt.ApplicationShortcut)
        self.shortcut_w.activated.connect(self._on_increase_x_linear_pressed)
        self.shortcut_x = QShortcut(QKeySequence(Qt.Key_X), self._widget)
        self.shortcut_x.setContext(Qt.ApplicationShortcut)
        self.shortcut_x.activated.connect(self._on_reset_x_linear_pressed)
        self.shortcut_s = QShortcut(QKeySequence(Qt.Key_S), self._widget)
        self.shortcut_s.setContext(Qt.ApplicationShortcut)
        self.shortcut_s.activated.connect(self._on_decrease_x_linear_pressed)
        self.shortcut_a = QShortcut(QKeySequence(Qt.Key_A), self._widget)
        self.shortcut_a.setContext(Qt.ApplicationShortcut)
        self.shortcut_a.activated.connect(self._on_increase_z_angular_pressed)
        self.shortcut_z = QShortcut(QKeySequence(Qt.Key_Z), self._widget)
        self.shortcut_z.setContext(Qt.ApplicationShortcut)
        self.shortcut_z.activated.connect(self._on_reset_z_angular_pressed)
        self.shortcut_d = QShortcut(QKeySequence(Qt.Key_D), self._widget)
        self.shortcut_d.setContext(Qt.ApplicationShortcut)
        self.shortcut_d.activated.connect(self._on_decrease_z_angular_pressed)

        self.shortcut_shift_w = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_W), self._widget)
        self.shortcut_shift_w.setContext(Qt.ApplicationShortcut)
        self.shortcut_shift_w.activated.connect(
            self._on_strong_increase_x_linear_pressed)
        self.shortcut_shift_x = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_X), self._widget)
        self.shortcut_shift_x.setContext(Qt.ApplicationShortcut)
        self.shortcut_shift_x.activated.connect(
            self._on_reset_x_linear_pressed)
        self.shortcut_shift_s = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_S), self._widget)
        self.shortcut_shift_s.setContext(Qt.ApplicationShortcut)
        self.shortcut_shift_s.activated.connect(
            self._on_strong_decrease_x_linear_pressed)
        self.shortcut_shift_a = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_A), self._widget)
        self.shortcut_shift_a.setContext(Qt.ApplicationShortcut)
        self.shortcut_shift_a.activated.connect(
            self._on_strong_increase_z_angular_pressed)
        self.shortcut_shift_z = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_Z), self._widget)
        self.shortcut_shift_z.setContext(Qt.ApplicationShortcut)
        self.shortcut_shift_z.activated.connect(
            self._on_reset_z_angular_pressed)
        self.shortcut_shift_d = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_D), self._widget)
        self.shortcut_shift_d.setContext(Qt.ApplicationShortcut)
        self.shortcut_shift_d.activated.connect(
            self._on_strong_decrease_z_angular_pressed)

        self.shortcut_space = QShortcut(
            QKeySequence(Qt.Key_Space), self._widget)
        self.shortcut_space.setContext(Qt.ApplicationShortcut)
        self.shortcut_space.activated.connect(self._on_stop_pressed)
        self.shortcut_space = QShortcut(
            QKeySequence(Qt.SHIFT + Qt.Key_Space), self._widget)
        self.shortcut_space.setContext(Qt.ApplicationShortcut)
        self.shortcut_space.activated.connect(self._on_stop_pressed)

        self._widget.stop_push_button.setToolTip(
            self._widget.stop_push_button.toolTip() + ' ' + self.tr('([Shift +] Space)'))
        self._widget.increase_x_linear_push_button.setToolTip(
            self._widget.increase_x_linear_push_button.toolTip() + ' ' + self.tr('([Shift +] W)'))
        self._widget.reset_x_linear_push_button.setToolTip(
            self._widget.reset_x_linear_push_button.toolTip() + ' ' + self.tr('([Shift +] X)'))
        self._widget.decrease_x_linear_push_button.setToolTip(
            self._widget.decrease_x_linear_push_button.toolTip() + ' ' + self.tr('([Shift +] S)'))
        self._widget.increase_z_angular_push_button.setToolTip(
            self._widget.increase_z_angular_push_button.toolTip() + ' ' + self.tr('([Shift +] A)'))
        self._widget.reset_z_angular_push_button.setToolTip(
            self._widget.reset_z_angular_push_button.toolTip() + ' ' + self.tr('([Shift +] Z)'))
        self._widget.decrease_z_angular_push_button.setToolTip(
            self._widget.decrease_z_angular_push_button.toolTip() + ' ' + self.tr('([Shift +] D)'))

        # timer to consecutively send twist messages
        self._update_parameter_timer = QTimer(self)
        self._update_parameter_timer.timeout.connect(
            self._on_parameter_changed)
        self._update_parameter_timer.start(100)
        self.zero_cmd_sent = False

    @Slot(str)
    def _on_topic_changed(self, topic):
        topic = str(topic)
        self._unregister_publisher()
        if topic == '':
            return
        try:
            self._publisher = rospy.Publisher(topic, Twist, queue_size=10)
        except TypeError:
            self._publisher = rospy.Publisher(topic, Twist)

    def _on_stop_pressed(self):
        # If the current value of sliders is zero directly send stop twist msg
        if self._widget.x_linear_slider.value() == 0 and \
                self._widget.z_angular_slider.value() == 0:
            self.zero_cmd_sent = False
            self._on_parameter_changed()
        else:
            self._widget.x_linear_slider.setValue(0)
            self._widget.z_angular_slider.setValue(0)

    def _on_x_linear_slider_changed(self):
        self._widget.current_x_linear_label.setText(
            '%0.2f m/s' % (self._widget.x_linear_slider.value() / RobotSteering.slider_factor))
        self._on_parameter_changed()

    def _on_z_angular_slider_changed(self):
        self._widget.current_z_angular_label.setText(
            '%0.2f rad/s' % (self._widget.z_angular_slider.value() / RobotSteering.slider_factor))
        self._on_parameter_changed()

    def _on_increase_x_linear_pressed(self):
        self._widget.x_linear_slider.setValue(
            self._widget.x_linear_slider.value() + self._widget.x_linear_slider.singleStep())

    def _on_reset_x_linear_pressed(self):
        self._widget.x_linear_slider.setValue(0)

    def _on_decrease_x_linear_pressed(self):
        self._widget.x_linear_slider.setValue(
            self._widget.x_linear_slider.value() - self._widget.x_linear_slider.singleStep())

    def _on_increase_z_angular_pressed(self):
        self._widget.z_angular_slider.setValue(
            self._widget.z_angular_slider.value() + self._widget.z_angular_slider.singleStep())

    def _on_reset_z_angular_pressed(self):
        self._widget.z_angular_slider.setValue(0)

    def _on_decrease_z_angular_pressed(self):
        self._widget.z_angular_slider.setValue(
            self._widget.z_angular_slider.value() - self._widget.z_angular_slider.singleStep())

    def _on_max_x_linear_changed(self, value):
        self._widget.x_linear_slider.setMaximum(
            value * RobotSteering.slider_factor)

    def _on_min_x_linear_changed(self, value):
        self._widget.x_linear_slider.setMinimum(
            value * RobotSteering.slider_factor)

    def _on_max_z_angular_changed(self, value):
        self._widget.z_angular_slider.setMaximum(
            value * RobotSteering.slider_factor)

    def _on_min_z_angular_changed(self, value):
        self._widget.z_angular_slider.setMinimum(
            value * RobotSteering.slider_factor)

    def _on_strong_increase_x_linear_pressed(self):
        self._widget.x_linear_slider.setValue(
            self._widget.x_linear_slider.value() + self._widget.x_linear_slider.pageStep())

    def _on_strong_decrease_x_linear_pressed(self):
        self._widget.x_linear_slider.setValue(
            self._widget.x_linear_slider.value() - self._widget.x_linear_slider.pageStep())

    def _on_strong_increase_z_angular_pressed(self):
        self._widget.z_angular_slider.setValue(
            self._widget.z_angular_slider.value() + self._widget.z_angular_slider.pageStep())

    def _on_strong_decrease_z_angular_pressed(self):
        self._widget.z_angular_slider.setValue(
            self._widget.z_angular_slider.value() - self._widget.z_angular_slider.pageStep())

    def _on_parameter_changed(self):
        self._send_twist(
            self._widget.x_linear_slider.value() / RobotSteering.slider_factor,
            self._widget.z_angular_slider.value() / RobotSteering.slider_factor)

    def _send_twist(self, x_linear, z_angular):
        if self._publisher is None:
            return
        twist = Twist()
        twist.linear.x = x_linear
        twist.linear.y = 0
        twist.linear.z = 0
        twist.angular.x = 0
        twist.angular.y = 0
        twist.angular.z = z_angular

        # Only send the zero command once so other devices can take control
        if x_linear == 0 and z_angular == 0:
            if not self.zero_cmd_sent:
                self.zero_cmd_sent = True
                self._publisher.publish(twist)
        else:
            self.zero_cmd_sent = False
            self._publisher.publish(twist)

    def _unregister_publisher(self):
        if self._publisher is not None:
            self._publisher.unregister()
            self._publisher = None

    def shutdown_plugin(self):
        self._update_parameter_timer.stop()
        self._unregister_publisher()

    def save_settings(self, plugin_settings, instance_settings):
        instance_settings.set_value(
            'topic', self._widget.topic_line_edit.text())
        instance_settings.set_value(
            'vx_max', self._widget.max_x_linear_double_spin_box.value())
        instance_settings.set_value(
            'vx_min', self._widget.min_x_linear_double_spin_box.value())
        instance_settings.set_value(
            'vw_max', self._widget.max_z_angular_double_spin_box.value())
        instance_settings.set_value(
            'vw_min', self._widget.min_z_angular_double_spin_box.value())

    def restore_settings(self, plugin_settings, instance_settings):
        value = instance_settings.value('topic', '/cmd_vel')
        value = rospy.get_param('~default_topic', value)
        self._widget.topic_line_edit.setText(value)

        value = self._widget.max_x_linear_double_spin_box.value()
        value = instance_settings.value('vx_max', value)
        value = rospy.get_param('~default_vx_max', value)
        self._widget.max_x_linear_double_spin_box.setValue(float(value))

        value = self._widget.min_x_linear_double_spin_box.value()
        value = instance_settings.value('vx_min', value)
        value = rospy.get_param('~default_vx_min', value)
        self._widget.min_x_linear_double_spin_box.setValue(float(value))

        value = self._widget.max_z_angular_double_spin_box.value()
        value = instance_settings.value('vw_max', value)
        value = rospy.get_param('~default_vw_max', value)
        self._widget.max_z_angular_double_spin_box.setValue(float(value))

        value = self._widget.min_z_angular_double_spin_box.value()
        value = instance_settings.value('vw_min', value)
        value = rospy.get_param('~default_vw_min', value)
        self._widget.min_z_angular_double_spin_box.setValue(float(value))