I made a simple grid of squares using tkinter and canvas and each square is meant to act like a button. I have it right now so that each time you click a button, it will change it own color. It cycles between four colors and white, meaning unselected. I would like to know how to bind not only a click, but a click-and-drag. So the user could click on a square, and while holding down, drag the cursor over the other squares that you would like to press.
I thought it would work with the <B1-Motion> event, but I find that that only causes the initially clicked button to cycle through its colors.
Here is my code:
import Tkinter as tk
class FreeformFrame(tk.Toplevel):
""" The FreeformFrame class creates a window for the selection of exact droplet placement for printing. """
def __init__(self, parent, master=None, **settings):
tk.Toplevel.__init__(self, parent)
self.parent = parent # parent widget
if master == None:
self.master = parent
else:
self.master = master
# ============ IMPORTED VARIABLES =========== #
# TEST PARAMETERS
self.res = 200 # microns
self.dim_x = 10 # mm
self.dim_y = 10 # mm
self.c_offset = 30 # Px - Adds some spacing between the edge of the canvas and where items are draw
self.text_offset = 8 # Px - Adds some spacing beween the edge of the canvas and where text is placed
# ===================== WINDOW VARIABLES ===================== #
self.tags_list = [] # Could be used later to target specific shapes drawn to the canvas
# ========= FRAME PARAMETERS ========= #
self.name = "Freeform Selection" # Text that appears at the top of the window
self.w_width = 700 # Pixel width of main Tk window
self.w_height = 700 # Pixel height of main Tk window
self.w_center_x = self.w_width/2 # px coordinate (x) of center of window
self.w_center_y = self.w_height/2 # px coordinate (y) of center of window
self.w_x_offset = 100# (self.master.scr_width-self.w_width)/2 # Pixel x offset for the Tk window.
self.w_y_offset = 100# (self.master.scr_height-self.w_height)/2 # Pixel y offset for the Tk window.
# ========== CHANNEL BUTTON SPACING ========== #
self.buttons_x = int(math.ceil(1000.*self.dim_x/(self.res)))
self.buttons_y = int(math.ceil(1000.*self.dim_y/(self.res)))
self.select = []
# ==================== CLASS INITIALIZATION ==================== #
# ========== TOPLEVEL WINDOW =========== #
self.wm_title(self.name)
self.geometry("%dx%d+%d+%d" % (self.w_width, self.w_height, self.w_x_offset, self.w_y_offset))
self.resizable(width=False,height=False)
# ========== CANVAS CONFIGURATION ========== #
# Start CanvasWell a.k.a. tk.Canvas in disguise preconfigured with buttons for selection
self.freeform_space = FreeformCanvas(self,self.master)
self.freeform_space.pack(fill="both", expand=True)
# Draw channel buttons
for col in range(self.buttons_x):
for row in range(self.buttons_y):
self.channel_button = ChannelButton(self.freeform_space,col,row)
class FreeformCanvas(tk.Canvas):
""" The FreeformCanvas represents the freeform selection space """
def __init__(self, parent, master=None, **kwargs):
tk.Canvas.__init__(self, parent, **kwargs)
self.parent = parent # parent widget
if master == None:
self.master = parent
else:
self.master = master
# ========== CANVAS PARAMETERS ========== #
self.c_offset = parent.c_offset # Adds some spacing between the edge of the canvas and where items are draw
self.text_offset = parent.text_offset # Adds some spacing beween the edge of the canvas and where text is placed
# Delimints the draw area
self.bbox = [self.c_offset, self.c_offset, self.parent.w_width-self.c_offset, self.parent.w_height-self.c_offset]
self.center_x = self.parent.w_center_x
self.center_y = self.parent.w_center_y
self.start_x = self.c_offset
self.start_y = self.c_offset
# TEST PARAMETERS
self.res = parent.res # microns
self.dim_x = parent.dim_x # mm
self.dim_y = parent.dim_y # mm
# Calculate the pixel scale
self.px_per_mm = (self.bbox[2]-self.bbox[0])/(self.dim_x) # pixels per mm
self.mm_per_px = self.px_per_mm **-1
# Label placement
self.label_coord = [self.text_offset, self.text_offset]
# XY display placement
self.xy_label_coord = [self.parent.w_width-self.text_offset, self.parent.w_height-self.text_offset]
# ========== CANVAS WELL INITIALIZATION ========== #
self.config(bg=PLATE_BG, width=self.parent.w_width, height=self.parent.w_height, highlightthickness=0, borderwidth=0)
self.bind("<Motion>", self.show_coordinates)
# Draw label for build type
self.label = self.create_text(self.label_coord, text="Freeform Selection", anchor="nw", fill=TEXT_PREVIEW_COLOR)
# Draw coordinate display
self.xy_label = self.create_text(self.xy_label_coord,text="Coord: (X = ? mm, Y = ? mm)", anchor="se", fill=TEXT_PREVIEW_COLOR)
def show_coordinates(self, event=None):
x_coord = self.mm_per_px*(event.x-(self.parent.w_width/2.0))
y_coord = self.mm_per_px*(event.y-(self.parent.w_height/2.0))
self.itemconfigure(self.xy_label, text="Coord: (X = %.3f mm, Y = %.3f mm)" % (x_coord, y_coord))
class ChannelButton(object):
def __init__(self, freeform_canvas, x, y):
super(ChannelButton, self).__init__()
# ========== IMPORTED VARIABLES ========== #
self.canvas = freeform_canvas
self.scale = freeform_canvas.px_per_mm
# ========= CANVAS BUTTON PARAMETERS ========= #
self.x = x # x index (column)
self.y = y # y index (row)
self.res = freeform_canvas.res # in microns
self.c_offset = freeform_canvas.c_offset
self.c_width = freeform_canvas.dim_x
self.c_height = freeform_canvas.dim_y
self.name = "Coord%i,%i" % (self.x,self.y)
self.scale = freeform_canvas.px_per_mm
self.channel_select = 0 # color
# Unselected: #FFFFFF (White)
# Channel 1: #DE0600 (Red)
# Channel 2: #032F95 (Blue)
# Channel 3: #09B400 (Green)
# Channel 4: #FFA100 (Orange)
# Center-to-center spacing between channel buttons
self.c_to_c = self.scale*self.res/1000.
self.center_x = self.c_offset+(self.scale*self.res/2000.)+self.c_to_c*self.x
self.center_y = self.c_offset+(self.scale*self.res/2000.)+self.c_to_c*self.y
# Start of bbox
self.start_x = self.c_offset+self.c_to_c*self.x
self.start_y = self.c_offset+self.c_to_c*self.y
# End of bbox
self.end_x = self.c_offset+(self.scale*self.res/1000.)+self.c_to_c*self.x
self.end_y = self.c_offset+(self.scale*self.res/1000.)+self.c_to_c*self.y
# Construct bbox
self.bbox = self.start_x, self.start_y, self.end_x, self.end_y
# Draw self
freeform_canvas.create_rectangle(self.bbox,tags=self.name,fill=UNSELECTED)
freeform_canvas.tag_bind(self.name,'<Button-1>', lambda event, loc=[self.x,self.y]:self.click_button(event,loc))
freeform_canvas.tag_bind(self.name,'<B1-Motion>', lambda event, loc=[self.x,self.y]:self.click_button(event,loc))
def click_button(self, event, loc):
x = loc[0]
y = loc[1]
print self.name
self.channel_select += 1
self.channel_select = self.channel_select % 5
if self.channel_select == 0:
self.canvas.itemconfig("Coord%i,%i"%(x,y),fill=UNSELECTED)
if self.channel_select == 1:
self.canvas.itemconfig("Coord%i,%i"%(x,y),fill=CH1)
if self.channel_select == 2:
self.canvas.itemconfig("Coord%i,%i"%(x,y),fill=CH2)
if self.channel_select == 3:
self.canvas.itemconfig("Coord%i,%i"%(x,y),fill=CH3)
if self.channel_select == 4:
self.canvas.itemconfig("Coord%i,%i"%(x,y),fill=CH4)
if __name__ == "__main__":
root = tk.Tk()
fff = FreeformFrame(root)
root.mainloop()
Thank you for your input!