Implement keysdown()

Author: BruceSherwood

labextension/vpython/src/glowcommlab.js

@@ -190,6 +190,7 @@ var lastcenter = vec(0,0,0)
 var lastrange = 1
 var lastautoscale = true
 var lastsliders = {}
+var lastkeysdown = []
 var interval = 33 // milliseconds
 
 function update_canvas() { // mouse location and other stuff
@@ -206,6 +207,23 @@ function update_canvas() { // mouse location and other stuff
 		var ray = cvs.mouse.ray 
 		if (!ray.equals(lastray)) {evt.ray = [ray.x,ray.y,ray.z]; dosend=true}
 		lastray = ray
+
+		var k = keysdown()
+		var test = true // assume keysdown() is same as lastkeysdown
+		if (k.length !== lastkeysdown.length) test = false
+		else {
+			for (var i=0; i<k.length; i++) {
+				if (k[i] !== lastkeysdown[i]) {
+					test = false
+					break
+				}
+			}
+		}
+		if (!test) {
+			evt.keysdown = lastkeysdown = k
+			dosend = true
+		}
+
 		// forward and range may be changed by user (and up with touch), and autoscale (by zoom)
 		if (cvs.userspin) {
 			var forward = cvs.forward

vpython/vpython.py

@@ -26,7 +26,7 @@
            'local_light', 'menu', 'meta_canvas', 'points', 'pyramid',
            'quad', 'radio', 'ring', 'simple_sphere', 'sleep', 'slider', 'sphere',
            'standardAttributes', 'text', 'textures', 'triangle', 'vertex',
-           'wtext', 'winput']
+           'wtext', 'winput', 'keysdown']
 
 __p = platform.python_version()
 _ispython3 = (__p[0] == '3')
@@ -40,6 +40,8 @@
 version = [__version__, 'jupyter']
 GSversion = [__gs_version__, 'glowscript']
 
+keysdownlist = [] # list of keys currently pressed
+
 # To print immediately, do this:
 #    print(.....)
 #    sys.stdout.flush()
@@ -3101,6 +3103,7 @@ def objz(self, obj, operation):
 
 ## key events conflict with notebook command mode; not permitted for now
     def handle_event(self, evt):  ## events and scene info updates
+        global keysdownlist
         ev = evt['event']
         if ev == 'pick':
             self.mouse.setpick( evt )
@@ -3185,6 +3188,8 @@ def handle_event(self, evt):  ## events and scene info updates
                 if 'autoscale' in evt and self.userzoom and not self._set_autoscale:
                     self._autoscale = evt['autoscale']
                 self._set_autoscale = False
+                if 'keysdown' in evt: keysdownlist = evt['keysdown']
+
 
     def bind(self, eventtype, whattodo):
         evts = eventtype.split()
@@ -4094,3 +4099,10 @@ def print_to_string(*args): # treatment of <br> vs. \n not quite right here
         s += str(a)+' '
     s = s[:-1]
     return(s)
+
+def keysdown():
+    global keysdownlist
+    keys = []
+    for k in keysdownlist: # return a copy of keysdownlist
+        keys.append(k)
+    return keys

vpython/vpython_libraries/glow.min.js

@@ -135,6 +135,7 @@
 var lastrange = 1
 var lastautoscale = true
 var lastsliders = {}
+var lastkeysdown = []
 var interval = 33 // milliseconds
 
 function update_canvas() { // mouse location and other stuff
@@ -151,6 +152,23 @@
 		var ray = cvs.mouse.ray 
 		if (!ray.equals(lastray)) {evt.ray = [ray.x,ray.y,ray.z]; dosend=true}
 		lastray = ray
+
+		var k = keysdown()
+		var test = true // assume keysdown() is same as lastkeysdown
+		if (k.length !== lastkeysdown.length) test = false
+		else {
+			for (var i=0; i<k.length; i++) {
+				if (k[i] !== lastkeysdown[i]) {
+					test = false
+					break
+				}
+			}
+		}
+		if (!test) {
+			evt.keysdown = lastkeysdown = k
+			dosend = true
+		}
+
 		// forward and range may be changed by user (and up with touch), and autoscale (by zoom)
 		if (cvs.userspin) {
 			var forward = cvs.forward

vpython/vpython_libraries/glowcomm.html

@@ -165,6 +165,7 @@ var lastcenter = vec(0,0,0)
 var lastrange = 1
 var lastautoscale = true
 var lastsliders = {}
+var lastkeysdown = []
 var interval = 33 // milliseconds
 
 function update_canvas() { // mouse location and other stuff
@@ -181,6 +182,23 @@ function update_canvas() { // mouse location and other stuff
 		var ray = cvs.mouse.ray 
 		if (!ray.equals(lastray)) {evt.ray = [ray.x,ray.y,ray.z]; dosend=true}
 		lastray = ray
+
+		var k = keysdown()
+		var test = true // assume keysdown() is same as lastkeysdown
+		if (k.length !== lastkeysdown.length) test = false
+		else {
+			for (var i=0; i<k.length; i++) {
+				if (k[i] !== lastkeysdown[i]) {
+					test = false
+					break
+				}
+			}
+		}
+		if (!test) {
+			evt.keysdown = lastkeysdown = k
+			dosend = true
+		}
+
 		// forward and range may be changed by user (and up with touch), and autoscale (by zoom)
 		if (cvs.userspin) {
 			var forward = cvs.forward