What's the easiest way to add a scrollbar to my VTK project ?
thanks
Update
def vtkSliderCallback2(obj, event):
sliderRepres = obj.GetRepresentation()
pos = sliderRepres.GetValue()
contourFilter.SetValue(0, pos)
SliderRepres = vtk.vtkSliderRepresentation2D()
min = 0 #ImageViewer.GetSliceMin()
max = 256 #ImageViewer.GetSliceMax()
SliderRepres.SetMinimumValue(min)
SliderRepres.SetMaximumValue(max)
SliderRepres.SetValue((min + max) / 2)
SliderRepres.SetTitleText("Slice")
SliderRepres.GetPoint1Coordinate().SetCoordinateSystemToNormalizedDisplay()
SliderRepres.GetPoint1Coordinate().SetValue(0.2, 0.6)
SliderRepres.GetPoint2Coordinate().SetCoordinateSystemToNormalizedDisplay()
SliderRepres.GetPoint2Coordinate().SetValue(0.4, 0.6)
SliderRepres.SetSliderLength(0.02)
SliderRepres.SetSliderWidth(0.03)
SliderRepres.SetEndCapLength(0.01)
SliderRepres.SetEndCapWidth(0.03)
SliderRepres.SetTubeWidth(0.005)
SliderRepres.SetLabelFormat("%3.0lf")
SliderRepres.SetTitleHeight(0.02)
SliderRepres.SetLabelHeight(0.02)
SliderWidget = vtk.vtkSliderWidget()
SliderWidget.SetInteractor(iren)
SliderWidget.SetRepresentation(SliderRepres)
SliderWidget.KeyPressActivationOff()
SliderWidget.SetAnimationModeToAnimate()
SliderWidget.SetEnabled(True)
SliderWidget.AddObserver("InteractionEvent", vtkSliderCallback2)
Just to be complete and for other users googling thing.
vtkSliderWidget will do what you want if you need it to set a value.
//edit based on your edit
If you want to get the value, you have to connect an event to the slider which is fired when the value is changed. Than retrieve this value and update accordingly. An example in C++ is found here
// I actually think my issue is that the callback function is invoked for each thumb position when I slide it. How can avoid that ? In other words I only want the last position to trigger the callback function...
Try coupling it to the EndInteractionEvent instead of to the InteractionEvent.
SliderWidget.AddObserver("EndInteractionEvent", vtkSliderCallback2)
// stuff
By the way, if you use python and VTK and need GUI stuff, I advice you to use the python QT and python qt widgets which ease up alot of this stuff. Some code of one of my old projects using QT+Python+VTK for GUI + python stuff:
self.verticalSlider = QtGui.QSlider(self.centralwidget)
self.verticalSlider.setOrientation(QtCore.Qt.Vertical)
self.verticalSlider.setObjectName("verticalSlider")
self.horizontalLayout.addWidget(self.verticalSlider)
// connect slider to a method onValueChange
QObject.connect(self.verticalSlider, SIGNAL("valueChanged(int)"),
self.setFibreVolumeOpacity)
def setFibreVolumeOpacity(self, value):
// do stuff here with slider value.
Related
I'm attempting to generate a height map from a noise texture. As far as I understand, in order to call get_pixel() on an image in this context, the image must first be locked. However, when I attempt to run the program, it exits with the error: Invalid call. Nonexistent function 'lock' in base 'StreamTexture'.
If I attempt to run it without locking the image, I get the error: Invalid call. Nonexistent function 'get_pixel' in base 'StreamTexture'.
I am certain that the instructions that I am following are for the same version of Godot I am running (3.1), so why is the engine telling me that lock() and get_pixel() are nonexistent functions?
My code is here:
extends Spatial
var width
var height
var heightData = {}
var vertices = PoolVector3Array()
var drawMesh = Mesh.new()
func _ready():
var noiseTexture = load("res://noiseTexture.png")
width = noiseTexture.get_width()
height = noiseTexture.get_height()
noiseTexture.lock()
for x in range(0, width):
for y in range(0, height):
heightData[Vector2(x,y)] = noiseTexture.get_pixel(x,y).r
noiseTexture.unlock()
for x in range(0, width-1):
for y in range(0, height-1):
createQuad(x,y)
var surfTool = SurfaceTool.new()
surfTool.begin(Mesh.PRIMITIVE_TRIANGLES)
for i in vertices.size():
surfTool.add_vertex(vertices[i])
surfTool.commit(drawMesh)
$MeshInstance.mesh = drawMesh
func createQuad(x,y):
#First half
vertices.push_back(Vector3(x, heightData[Vector2(x,y)], -y))
vertices.push_back(Vector3(x, heightData[Vector2(x,y+1)], -y-1))
vertices.push_back(Vector3(x+1, heightData[Vector2(x+1,y+1)], -y-1))
#Second Half
vertices.push_back(Vector3(x, heightData[Vector2(x,y)], -y))
vertices.push_back(Vector3(x+1, heightData[Vector2(x+1,y+1)], -y-1))
vertices.push_back(Vector3(x+1, heightData[Vector2(x+1,y)], -y))
Any help is greatly appreciated.
EDIT - I have (tried) to implement the changes that were suggested in the comments (yet I still don't know what to do with the color variable) and have attached a screenshot of my resulting code, as well as some comments I have made to try and explain to myself why the process SHOULD be working (I think). It also shows my node structure, which is why I opted to display this as an image. However, when I try to run this, the program crashes with the error displayed.
Check the docs;
StreamTexture does not have the method lock.
I think the class you are looking to use is Image. The Texture class is typically intended for drawing on the screen or applying to a Material
var noiseImage = Image.new()
noiseImage.load("res://noiseTexture.png")
noiseImage.lock() # Lock the image here
var color = noiseImage.get_pixel(10, 10) # Replace with your height map population
PS:
Just to let you know, I had a lot of issues with memory usage here so make sure you test that also (C# has bad garbage collector though).
You might need to dispose of the image, surface tool, and array mesh (If you remove the terrain object) to maintain optimum performance.
I have run into similar issues with generating heightmap terrains.
nathanfranke is correct and his solution will work.
If you for some reason use an ImageTexture you can call get_data() on that to get the underlying Image. Then you call lock() on the Image just like nathan says in his answer.
Take care to check that your coordinates for get_pixel() are correct. You can set a breakpoint by clicking on the very left edge of the line of code.
I mention this because I was very frustrated until I realized that my coordinate calculations were all int which resulted in the sampled pixel always being at <0,0>.
Here is part of my code for sampling an image into the HeightMapShape.map_data for Bullet heightmap collisions:
var map_w = shape.map_width
var map_h = shape.map_depth
var img_w = img.get_width()
var img_h = img.get_height()
img.lock()
for y in range(0, map_h):
py = float(img_h) * (float(y) / float(map_h))
for x in range(0, map_w):
px = float(img_w) * (float(x) / float(map_w))
index = y * img_h + x
pix = img.get_pixel(px, py)
shp.map_data[index] = pix.r * heightmap_height + heightmap_offset
Ultimately I want pyqtgraph to display a single GraphicsObject simultaneously in several ViewBoxes, sharing a single scene.
At the same time I want to have some other GraphicsObjects in a single ViewBox only.
Something like this:
vb0 = ViewBox()
vb1 = ViewBox()
# shown only in first ViewBox vb0
local_item = GraphicsObject()
# shown in all ViewBoxes
global_item = GraphicsObject()
vb0.addItem(local_item)
assert vb0.scene() is vb1.scene()
# the magic function i am looking for
vb0.scene().addItemGlobally(global_item)
So very naively I looked into the ViewBox sourcecode and reproduced the steps for addItem() like here:
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore as qc, QtGui as qg, QtWidgets as qw
class Polygon(pg.GraphicsObject):
"""Just a Triangle..."""
app = qw.QApplication([])
viewer = pg.GraphicsWindow()
vb0 = viewer.addViewBox(0, 0)
vb1 = viewer.addViewBox(0, 1)
viewer.show()
poly_yellow = Polygon((125, 125, 0, 255))
scene = vb0.scene()
added_items = vb1.addedItems = vb0.addedItems
child_group = vb1.childGroup = vb0.childGroup
child_group.setParent(scene)
child_group.itemsChangedListeners.append(vb1)
# here reproducing steps found in addItem()
if scene is not poly_yellow.scene():
scene.addItem(poly_yellow)
poly_yellow.setParentItem(child_group)
added_items.append(poly_yellow)
vb0.updateAutoRange()
# vb1.updateAutoRange()
# checking if ViewBoxes share relevant attributes
assert vb0.scene() is vb1.scene()
assert vb0.scene() is poly_yellow.scene()
assert vb0.addedItems is vb1.addedItems
assert vb0.childGroup is vb1.childGroup
app.exec_()
Running this gives me two ViewBoxes, but only vb0 showing the triangle. Also this approach would give me global only Items. Is there any way to get something like local/global items without re-implementing ViewBoxes completely?
EDIT: I think it is impossible to achieve what I want with pyqtgraph ViewBoxes. A transform of the global items must happen just before the painting.
I found it is not easily doable using ViewBox. However, it is possible to us pyqtgraphs GraphicsView, implementing a lot of functionality found in the ViewBox class already.
My approach now is to generate as many GraphicsView as I need, and set them all to one scene via GraphicsView.setScene()
The scene contains the 'global' items, displayed in every View. The Viewspecific, local Items are drawn using the GraphicsView.drawBackground() function.
I haven't tested it to much, but it seems quite good working, for the case, were several thousend items are added to the scene, but only few items are drawn to the background.
I am somewhat new to GUI programming and very new to PyQt, and I'm trying to build a GUI that displays a list of questions. I have created a QuestionBank class that subclasses QWidget and overrides the .show() method to display the list properly. I have tested this alone and it works correctly. However, the list of questions can be quite long, so I've been trying to make it scrollable. Rather than add a QScrollBar to the widget and then set up the event triggers by hand, I've been trying to my QuestionBank widget in a QScrollArea based on the syntax I've seen in examples online. While the scroll area shows up fine, it does not at all display the question bank but rather just shows a blank outline.
The QuestionBank class looks like this:
class QuestionBank(QWidget):
BUFFER = 10 # space between questions (can be modified)
def __init__(self, parent, questions):
# `parent` should be the QWidget that contains the QuestionBank, or None if
# QuestionBank is top level
# `questions` should be a list of MasterQuestion objects (not widgets)
QWidget.__init__(self, parent)
self.questions = [MasterQuestionWidget(self, q) for q in questions]
self.bottomEdge = 0
def show(self, y=BUFFER):
QWidget.show(self)
for q in self.questions:
# coordinates for each each question
q.move(QuestionBank.BUFFER, y)
q.show()
# update y-coordinate so that questions don't overlap
y += q.frameGeometry().height() + QuestionBank.BUFFER
self.bottomEdge = y + 3 * QuestionBank.BUFFER
# ... other methods down here
My code for showing the scroll bar looks like this:
app = QApplication(sys.argv)
frame = QScrollArea()
qs = QuestionBank(None, QFileManager.importQuestions())
qs.resize(350, 700)
frame.setGeometry(0, 0, 350, 300)
frame.setWidget(qs)
frame.show()
sys.exit(app.exec_())
I have tried many variants of this, including calling resize on frame instead of qs, getting rid of setGeometry, and setting the parent of qs to frame instead of None and I have no idea where I'm going wrong.
If it helps, I'm using PyQt5
Here is the question bank without the scroll area, to see what it is supposed to look like:
Here is the output of the code above with the scroll area:
This variation on the code is the only one that produces any output whatsoever, the rest just have blank windows. I'm convinced its something simple I'm missing, as the frame is obviously resizing correctly and it obviously knows what widget to display but its not showing the whole thing.
Any help is much appreciated, thank you in advance.
In my new application I want when the mouse is over the entry() widget to change color (this I know how to do it) but I want the color to change gradually, not immediately.
This is my code:
# User_Line Focus In/Out
def User_Line_Focus_In(self, event):
self.User_Line.configure(bg = "#DCDCDC")
def User_Line_Focus_Out(self, event):
self.User_Line.configure(bg = "#FFFFFF")
You need to create a method which increments the colour and you need to use tkinter's after which registers an alarm callback that is called after a given time. You then need to reference it recursively in order to get the fading effect you want.
def incrementHex(hex_str, increment): #with hex_str in format "#FFFFFF" or any colour
red = int(hex_str[1:3],16) #specifies base for integer conversion
green = int(hex_str[3:5],16)
blue = int(hex_str[5:],16)
red += increment #increment can be negative
green += increment
blue += increment
new_hex_str = "#" + str(hex(red)) + str(hex(blue)) + str(hex(green))
return new_hex_str
def Fade(self, start_hex, increment):
new_hex = self.incrementHex(start_hex, increment)
self.User_Line.configure(bg = new_hex)
#where self.master is the parent widget as defined in the __init__ method...
self.master.after(50,lambda: self.Fade(new_hex, increment)) #or any time interval in milliseconds
#you'll probably need some code to stop it fading here, but I'll let you tackle that one :)
def User_Line_Focus_In(self, event):
self.Fade("#FFFFFF",-1) #could be any colour and increment
I haven't been able to test it, but I think it should work in principle. An extension of this would be to have different increments for red, green and blue.
I think you are going to have to pull up your socks on this one and do some coding (tkinter doesn't have this built in)
So what you are looking for is :
An algorithm to go from color one to color two and get intermediate colors. (Hex values are just numbers in base 16 but they can be added or subtracted like normal numbers)
The simplest solution would be to just run the algorithm (color_difference here)
def fade_colors(event, new_color):
old_color = event.widget.cget('bg')
for color in color_difference(old_color, new_color):
event.widget.configure(color)
time.sleep(0.1)
widget.bind('<Enter>', lambda event: fade_colors(event, color))
You might also like to cancel the operation if the user leaves the widget. Take a look at the built in sched module.
If you find your gui becomes unresponsive during the fading you could consider using the after method, you can read this excellent blog post on non blocking gui techniques in python and tkinter. This may not be an issue if you cancel the callback as soon as the user leaves the widget (thus freeing up tkinter to handle his other actions)
I am trying to make a simon says game and am having trouble collecting the users choice to compare against the computer's pattern. I am using four buttons to select the colors that flash on the screen. The problem I am having is my program continues to chug along even if my user hasn't selected a color yet, despite my best efforts to stop it, what can I do to stop the program? Here is my code...
Sequence[]
PosColors = ["Yellow","Red","Blue","Green"]
PlayerChoice[]
Score = 0
def Game(Sequence, PlayerChoice,Score):
Score += 1
PlayerChoice = []
Number = randint(0,3)
Sequence.append(PosColors[Number])
for i in Sequence:
RunTime = Score * 1000
Gui.after(1000, blink, rect, SquareCanvas , i)
RunTime = (Score + 1) * 1000
Gui.after(2000, blink, rect, SquareCanvas , White)
X = len(Sequence)
Index = 0
Color = " "
while Color != " ":
BlueButton.config(command = partial(setSelection,NeonBlue))
RedButton.config(command = partial(setSelection,NeonRed))
YellowButton.config(command = partial(setSelection,NeonYellow))
GreenButton.config(command = partial(setSelection,NeonGreen))
Color = getSelection()
print(Color)
while Color != " ":
PlayerTurn(Sequence,PlayerChoice,Score,Index)
X -= 1
Index +=1
def setSelection(Color):
if Color == NeonBlue:
return "NeonBlue"
elif Color == NeonRed:
return "NeonRed"
elif Color == NeonGreen:
return "NeonGreen"
elif Color == NeonYellow:
return "NeonYellow"
def getSelection():
return TheColor
def PlayerTurn(Sequence, PlayerChoice,Score,Index):
PlayerChoice.append(Color)
print(PlayerChoice)
Label1.config(text = 'Well done! \nYou advance to the next round!')
I am planning on passing this through a checker and to loop it until there is an error but I need to get past this front loop first... I know my logic works as I created it using just lists and the command line before moving on the the graphical portion I just need to know how to get the program to stop to collect the user guess, especially as the length of the pattern gets larger. Originally I had the command function included later where I build my Buttons but this placement seems to get as close as possible to what I am looking for. Any help is appreciated thank you
You're going to need to rethink your main program logic. Tkinter is designed such that you should never have your own infinite loop. Tkinter already has an infinite loop -- the mainloop() method of the root window. You can't write logic that waits for input from the user. You have to think of the GUI as in a perpetual state of waiting, and you need set up handlers (button callbacks or event bindings) to react to events.
You also need to understand that a button command can't "return" anything. "Can't" is a bit strong since it obviously can, but there's nothing waiting for the result -- no place to return it to. You need to design your button function such that it sets a global or instance variable.