1 00:00:01,680 --> 00:00:05,610 OK, in the last video, we drew a couple straight lines in this video, I want to start to introduce 2 00:00:05,610 --> 00:00:09,690 the mouse into this because, you know, when we're drawing, we're not going to programmatically create 3 00:00:09,690 --> 00:00:10,500 these lines like this. 4 00:00:10,500 --> 00:00:12,630 We're just going to drag our mouse around the screen. 5 00:00:12,630 --> 00:00:16,570 And hopefully that will create the color on the screen and draw the lines that way. 6 00:00:16,590 --> 00:00:17,940 So how do we start to do that? 7 00:00:17,940 --> 00:00:24,510 Well, any time you're doing something like adding keyboard events or mouse events, you're actually 8 00:00:24,630 --> 00:00:27,870 finding our widget and that's what it's called. 9 00:00:27,870 --> 00:00:28,910 It's binding a widget. 10 00:00:28,920 --> 00:00:34,470 And when you bind a widget, you're saying, hey, when you do something in this widget with, for instance, 11 00:00:34,470 --> 00:00:37,830 the mouse, sort of connect it to that widget. 12 00:00:37,830 --> 00:00:38,100 Right. 13 00:00:38,120 --> 00:00:44,790 So we're saying when we want to, like, move the mouse around the canvas record that make make note 14 00:00:44,790 --> 00:00:46,350 of that, bind that. 15 00:00:46,530 --> 00:00:46,740 Right. 16 00:00:46,840 --> 00:00:48,540 So to do that, we just bind it. 17 00:00:48,810 --> 00:00:50,790 We just bind the mouse to the canvas. 18 00:00:51,090 --> 00:00:52,410 And it's fairly simple. 19 00:00:52,410 --> 00:00:54,750 We just call my canvas dot bind. 20 00:00:56,390 --> 00:00:59,360 And this is a function now, what do we want to capture? 21 00:00:59,570 --> 00:01:04,100 Well, in this case, we want to capture the mouse moving around, but not just the mouse moving around. 22 00:01:04,400 --> 00:01:09,620 We also want to capture when we click the mouse button and then drag around, because that's how we're 23 00:01:09,620 --> 00:01:10,220 going to draw. 24 00:01:10,220 --> 00:01:11,480 We're going to click the mouse button. 25 00:01:11,630 --> 00:01:16,760 And while we're holding the mouse button down, we want to move the mouse around and then draw. 26 00:01:16,880 --> 00:01:19,940 And then when we let off the mouse button, we want it to stop drawing. 27 00:01:20,100 --> 00:01:26,990 So that is a special kind of mouse binding called One Motion. 28 00:01:27,140 --> 00:01:34,280 And to do that, to designate that, we use these brackets and then we just type B one as capital B 29 00:01:34,490 --> 00:01:35,630 dash motion. 30 00:01:35,900 --> 00:01:39,800 So B one stands for button one, which is the left mouse button. 31 00:01:40,020 --> 00:01:46,250 So we're going to left click the mouse button motion means we're moving the mouse right where it's motion. 32 00:01:46,430 --> 00:01:48,540 So that's how you bind that. 33 00:01:48,560 --> 00:01:54,980 Now what do we want to happen when we do that, when we click the canvas and move the mouse around, 34 00:01:54,980 --> 00:01:56,000 what do we want to happen? 35 00:01:56,180 --> 00:01:59,370 Or we want to run a function and we want to call that function paint. 36 00:01:59,600 --> 00:02:03,260 Now, we haven't actually created this function yet, so we need to do that now. 37 00:02:03,680 --> 00:02:05,200 So let's go ahead and do that. 38 00:02:05,810 --> 00:02:08,360 And I'm just going to come up here to the top. 39 00:02:09,660 --> 00:02:14,610 Of our program here, I like to do my functions all the time top and let's create a function called 40 00:02:14,610 --> 00:02:15,060 paint. 41 00:02:15,300 --> 00:02:20,780 Now, every time we create a function with a binding, we have to pass in an event. 42 00:02:21,000 --> 00:02:23,790 And here I'm passing in E stands for event. 43 00:02:23,950 --> 00:02:25,200 You could also type event. 44 00:02:25,680 --> 00:02:30,620 You could call this Bob if you want, but the convention is called E, which stands for event. 45 00:02:30,930 --> 00:02:31,800 What is an event. 46 00:02:32,040 --> 00:02:34,850 An event is when you do something right. 47 00:02:34,870 --> 00:02:41,600 So when you're moving your mouse around, that's a mouse event that you've now binded to the canvas. 48 00:02:41,910 --> 00:02:45,000 So it just keeps track of where the mouse is as you're moving it around. 49 00:02:45,300 --> 00:02:46,920 That's what the event is. 50 00:02:46,920 --> 00:02:48,510 It's the moving of the mouse. 51 00:02:48,690 --> 00:02:52,650 And by passing it into this function, we can keep track of where the mouse is. 52 00:02:52,860 --> 00:02:58,260 And later on, we're going to use that to say, draw where the mouse is when you click the button. 53 00:02:58,440 --> 00:02:58,790 Right. 54 00:02:59,010 --> 00:03:02,900 A little convoluted maybe, but it'll make more sense as we actually create it. 55 00:03:02,910 --> 00:03:05,730 So for now, we're not going to do that just yet. 56 00:03:05,730 --> 00:03:06,570 We're not there yet. 57 00:03:06,720 --> 00:03:08,460 For now, we just want to do something. 58 00:03:08,460 --> 00:03:09,240 What do we want to do? 59 00:03:09,450 --> 00:03:12,690 Well, let's change the color of the canvas whenever we click on it. 60 00:03:12,900 --> 00:03:19,860 So let's go my underscore canvas dot config and we use the config function to update widgets after the 61 00:03:19,860 --> 00:03:20,910 program has run. 62 00:03:21,270 --> 00:03:23,040 So we're running the program. 63 00:03:23,040 --> 00:03:24,090 Then we want to configure it. 64 00:03:24,090 --> 00:03:24,960 What do we want to do? 65 00:03:25,230 --> 00:03:27,720 Or remember down here we had the background color as white. 66 00:03:28,080 --> 00:03:30,390 We can change the background color to anything else. 67 00:03:30,390 --> 00:03:31,860 Let's just change it to black. 68 00:03:31,890 --> 00:03:32,210 Right? 69 00:03:32,490 --> 00:03:37,800 So when we click on the canvas and drag the mouse, it should change to black if we've done it right. 70 00:03:37,800 --> 00:03:42,990 So let's go and save this and head back over here to your terminal and run this guy again. 71 00:03:43,500 --> 00:03:50,010 And you can see we still got our red lines on here, so I'm about to click boom changes it to black. 72 00:03:50,010 --> 00:03:54,060 If I click again, it doesn't change it back again because we haven't programmed it to do that. 73 00:03:54,060 --> 00:03:59,340 It just changes the changes that the black and the red lines haven't changed, just the canvas background 74 00:03:59,340 --> 00:03:59,730 color. 75 00:04:00,060 --> 00:04:05,490 But we've now created a binding for our mouse. 76 00:04:05,490 --> 00:04:06,870 It's now bound to this widget. 77 00:04:06,870 --> 00:04:11,370 And we can test this by, for instance, coming down here and I'm going to click the button and drag 78 00:04:11,370 --> 00:04:12,210 down here. 79 00:04:12,630 --> 00:04:13,470 Nothing happens. 80 00:04:13,470 --> 00:04:14,400 Can you hear me clicking? 81 00:04:16,570 --> 00:04:21,130 My mouse is pretty silent, but I'm clicking the mouse and dragging, and nothing happens only when 82 00:04:21,130 --> 00:04:26,950 we do it in the canvas because we only binded it bounded around, I guess, to the canvas. 83 00:04:26,960 --> 00:04:27,880 So if I do it here. 84 00:04:30,070 --> 00:04:34,450 It changes color so very cool and very, very easy, and that's all there is to that. 85 00:04:34,460 --> 00:04:39,790 So we are now a good portion of a good way towards drawing. 86 00:04:39,790 --> 00:04:41,880 We've got we know how to draw a line. 87 00:04:42,070 --> 00:04:49,020 We know how to bring the mouse into play and sort of have that deal with the function really quickly. 88 00:04:49,030 --> 00:04:50,680 We can look at this, be one motion. 89 00:04:50,690 --> 00:04:52,750 Remember, this is pressing button one. 90 00:04:52,960 --> 00:04:56,860 If we just do motion, that just means we're moving the mouse into there. 91 00:04:57,100 --> 00:04:58,360 We're not actually clicking a button. 92 00:04:58,360 --> 00:05:02,470 So if we save this and just look at this real quick, if we run this. 93 00:05:04,720 --> 00:05:10,120 So here's my mouse, as soon as I bring it in here, boom, it changes color because all it takes is 94 00:05:10,120 --> 00:05:13,600 just a little motion of the mouse in there and then it runs. 95 00:05:13,600 --> 00:05:18,190 So we want a BE1 motion because we're always going to be clicking the button to draw. 96 00:05:18,340 --> 00:05:18,750 Right. 97 00:05:19,390 --> 00:05:24,220 But if for some reason you didn't want that, you could just call motion. 98 00:05:24,580 --> 00:05:27,390 So the other button, I believe, is B3. 99 00:05:27,400 --> 00:05:33,610 If we save this and, you know, my computer mice, mouses, whatever the plural is for a computer, 100 00:05:33,610 --> 00:05:35,600 mouse usually has two buttons. 101 00:05:35,600 --> 00:05:37,650 So let's see the right button. 102 00:05:38,140 --> 00:05:38,560 Yeah. 103 00:05:38,740 --> 00:05:41,500 If I click the right button, boom, that's B three. 104 00:05:41,890 --> 00:05:43,060 And why not be two. 105 00:05:43,060 --> 00:05:45,370 Because back in the day computer mouses. 106 00:05:45,580 --> 00:05:46,300 It sounds weird to me. 107 00:05:46,310 --> 00:05:51,490 Computer mice used to have three buttons, one in the middle usually now they have a ruler in the middle, 108 00:05:51,640 --> 00:05:53,710 not a third mouse button. 109 00:05:53,710 --> 00:05:56,320 So Kintyre has button. 110 00:05:56,620 --> 00:06:01,750 Button one is the left one, button three is the right one and button two is probably the middle one. 111 00:06:01,750 --> 00:06:05,110 But you're going to be hard pressed to find a mouse with three buttons these days. 112 00:06:05,290 --> 00:06:07,240 So that's all there is to this. 113 00:06:07,240 --> 00:06:12,550 In the next video, we're going to start to bring in bring this all together, use the mouse motion 114 00:06:12,550 --> 00:06:17,410 and creating lines to start to draw on the actual canvas with the mouse. 115 00:06:17,410 --> 00:06:18,940 And that'll be coming up in the next video.