- Listening for Events
- Mouse Detection
- The SimpleButton Class
- Invisible Buttons
- Animated Buttons and the Movie Clip Symbol
- Complex Buttons
- Button-tracking Options
- Changing Button Behavior
- Creating Buttons Dynamically
- Keyboard Detection
- The Contextual Menu
- Creating Continuous Actions
- A Summary of Events
This chapter is from the book
This chapter is from the book
This chapter is from the book
Complex Buttons
You can use a combination of invisible buttons, animated buttons, and movie clips to create objects with complex behaviors
such as pull-down menus. The pull-down (or pop-up) menu is a kind of button that is common in operating systems and Web interfaces,
and is useful for presenting several choices under a single heading. The functionality consists of a single button that expands
to show more buttons and collapses when a selection has been made 
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To build your own pull-down menu, one effective strategy is to nest symbols inside each other. A simple way is to place buttons inside a movie clip. The buttons specify which frames within the movie clip timeline to play. Whether the menu is expanded or collapsed is determined within the movie clip. Placing an instance of this movie clip on the Stage allows you to access either the expanded or collapsed state independently of what’s happening in your main movie.
To create a simple pull-down menu
- Create a button symbol that will be used for the top menu button as well as the choices in the expanded list.
- Add a filled rectangle to the Up, Over, Down, and Hit keyframes
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- Create a new movie clip symbol.
Enter symbol-editing mode for the movie clip.
- Insert a new keyframe at a later point in the movie clip Timeline.
You now have two keyframes inside your movie clip symbol. The first one will contain the collapsed state of your menu, and the second one will contain its expanded state
.
- Drag one instance of your button symbol into the first keyframe, and add text over the instance to describe the button.
This is the collapsed state of your menu.
- Drag several instances of your button symbol into the second keyframe, align them with one another, and add text over these
instances to describe the buttons.
This is the expanded state of your menu.
- Add a new layer, and place frame labels to mark the collapsed and expanded keyframes
.
In the Frame Label field of the Properties inspector, enter collapsed for the first keyframe and expanded for the second keyframe.
The frame labels let you see clearly the collapsed and expanded states of your movie clip, and let you use the gotoAndStop() action with frame labels instead of frame numbers.
- Select the button instance in the first keyframe, and give it an instance name.
- Add a new layer; select the first keyframe in that layer, and open the Actions panel.
- In the first line of the Script pane, add the action stop().
Without this stop() in the first frame of your movie clip, the menu would open and close repeatedly because of the automatic cycling of movie clips. The stop() action ensures that the movie clip stays on frame 1 until you click the menu button
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- On the next line of the Script pane, add an event listener for the button that is on the first keyframe of your movie clip:
pick_btn.addEventListener(MouseEvent.CLICK, expandmenu);
This listener listens for a mouse click on the button called pick_btn
.
- On the next available line of the Script pane, add a function that goes to the expanded keyframe of the movie clip, like so:
function expandmenu(myevent:MouseEvent):void { this.gotoAndStop("expanded"); }When this function is called, the current timeline is targeted (with the keyword this) and the playhead goes to the frame labeled expanded. Make sure that the frame label is within quotation marks.
- Select the first button instance on the last keyframe, and give it an instance name.
- In the layer with your ActionScript, select the frame above the expanded keyframe, and add a new keyframe.
In this keyframe, you’ll add the code for the buttons in the expanded menu.
You have to put more code here because you can’t add event-handler code to buttons until they’re present on the Stage. Otherwise, Flash won’t find the button instances and can’t reference them from the code
.
- With your new keyframe selected, open the Actions panel and add an event listener for the first button in the expanded keyframe:
pick2_btn.addEventListener(MouseEvent.CLICK, collapsemenu);
This listener listens for a mouse click on the button called pick2_btn.
- Next, add a function that goes back to the collapsed keyframe, like so:
function collapsemenu(myevent:Mouse Event):void { this.gotoAndStop("collapsed"); } - Assign instance names to each of the remaining button instances on this keyframe, and repeat step 15 to add event-handler
code for each of them
.
- Return to the main movie Timeline, and place an instance of your movie clip on the Stage.
- Choose Control > Test Movie > in Flash Professional to see how your pull-down menu works.
When you click the first button, the buttons for your choices appear because you direct the playhead to go to the expanded keyframe on the movie clip timeline. When you click one of the buttons in the expanded state, the buttons disappear, returning you to the collapsed keyframe of the movie clip timeline. All this happens independently of the main movie Timeline, where the movie clip instance resides
.
At this point, you’ve created a complex button that behaves like a pull-down menu but doesn’t actually do anything (except modify itself). In Chapter 5, “Controlling Multiple Timelines,” you’ll learn how to make timelines communicate with one another, which enables you to create complex navigation systems.
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