slider added

jhavl · jhavl · commit 7ba50d439468 · 2021-02-15T14:18:26.000+10:00
diff --git a/roboticstoolbox/backends/Swift/Swift.py b/roboticstoolbox/backends/Swift/Swift.py
@@ -9,6 +9,7 @@
 import spatialmath as sm
 import time
 from queue import Queue
+import json
 
 _sw = None
 sw = None
@@ -72,6 +73,12 @@ def __init__(self, realtime=True, display=True):
         self.outq = Queue()
         self.inq = Queue()
 
+        # Number of custom html elements added to page for id purposes
+        self.elementid = 0
+
+        # Element dict which holds the callback functions for form updates
+        self.elements = {}
+
         self.realtime = realtime
         self.display = display
 
@@ -383,6 +390,46 @@ def stop_recording(self):
                 "You must call swift.start_recording(file_name) before trying"
                 " to stop the recording")
 
+    def add_slider(
+            self, cb, min=0, max=100, step=1, value=0, desc='', unit=''):
+        """
+        Add a range-slider to the page
+
+        :param cb: A callback function which is executed when the value of the
+            slider changes. The callback should accept one argument which
+            represents the new value of the slider
+        :type cb: function
+        :param min: the minimum value of the slider, optional
+        :type min: float
+        :param max: the maximum value of the slider, optional
+        :type max: float
+        :param step: the step size of the slider, optional
+        :type step: float
+        :param desc: add a description of the slider, optional
+        :type desc: str
+        :param unit: add a unit to the slider value, optional
+        :type unit: str
+
+        ``env.add_slider()`` adds a slider to the graphical
+            environment.
+
+        """
+
+        id = 'customelement' + str(self.elementid)
+        self.elementid += 1
+        self.elements[id] = cb
+
+        self._send_socket(
+            'add_element',
+            ['slider', id, min, max, step, value, desc, unit])
+
+    def process_events(self):
+        events = self._send_socket('check_elements')
+        events = json.loads(events)
+
+        for event in events:
+            self.elements[event](events[event])
+
     def _step_robots(self, dt):
 
         for robot_object in self.robots:
