The Options Menu

[MUSIC] 0:00 Hey there. 0:04 I'm Ben, and in this workshop we're going to learn how to use the options menu. 0:05 The options menu is the set of options you usually see at the top of an application, 0:10 and it's where you should place any actions related to the current activity. 0:14 Let's take a look at the app we'll be making to get acquainted with 0:18 the options menu. 0:20 In this workshop we'll be making an app to let us change the colors 0:22 of a few preloaded images. 0:25 Up here is the options menu, where we have two items being displayed, and 0:27 four more in the overflow menu. 0:32 The first item lets us cycle through the three images. 0:35 And the second one toggles the image between color, and black and white. 0:39 In the overflow menu we have a check box for each color channel. 0:45 And if we uncheck one, that color is removed from the image. 0:48 Finally, the Reset button just resets the image to normal. 0:53 And one more thing, if we have a black and 0:57 white image, it doesn't really make sense to remove color from it. 0:59 So we're not going to show the color options unless it's 1:04 actually a color image. 1:07 That's enough about the project for now, let's start making it. 1:08 If you'd like to follow along, pause me and 1:12 download the starter project from the teacher's notes below. 1:14 All right, now that we've got our project, let's open up MainActivity and 1:17 see what we're working with. 1:20 At the top we've got a few fields. 1:27 There's one for our imageView, followed by an array to store our resource IDs, and 1:30 an imageIndex to store which resource ID we're using. 1:35 Then there's a boolean variable to determine if the image is in color. 1:39 And finally three more booleans to determine whether each color 1:43 should be on or off. 1:47 In the onCreate method, we just set our layout, 1:50 populate the imageView field, and then call the loadImage method. 1:53 If you try to load a large image into an imageView, 1:57 Android will throw an out of memory error. 2:01 However, by using the Glide library, we don't have to worry about that, and 2:03 we can just load the image right into the imageView. 2:07 At the bottom of the class, we have two more functions that aren't being used yet. 2:11 The first is updateSaturation, which will toggle the image between color, and 2:15 black and white, depending on the value of our color field. 2:19 The second method is updateColors. 2:23 This method will set the colors of our image based on the values of the red, 2:27 green, and blue fields. 2:32 All right, that should be enough to get us started. 2:33 In the next video we'll start implementing our options menu. 2:36