Lessons
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Scratch Interface
Scratch is a graphical programming language. Applications are created using different types of media, including graphics and sound, and by using scripts made up of different code blocks. The applications are created using the interface shown below:
Stage
The Stage is where you see your stories, games, and animations come to life. Sprites move and interact with one another on the Stage.
As you can see, the X-axis runs from coordinates 240 to –240, and the Y-axis coordinate runs from coordinates 180 to –180. The middle of the stage has a coordinate location of (0, 0). Scratch keeps you informed of the pointer’s location whenever it is moved over the stage by displaying its (X, Y) coordinate position in the mouse x: and mouse y: fields just beneath the bottom-right side of the stage. New Sprite Buttons
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These buttons allow you to create new sprites and/or add new sprites to an existing application. You have 3 ways of getting new sprites onto your stag:
If you want to delete a sprite, select the scissors from the Toolbar and click on the sprite. Or right-click on the sprite and select delete from the pop-up menu. Sprite List
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Scratch applications are made up of sprites that interact with one another as they move around the stage. Each sprite that makes up a Scratch application is displayed as a thumbnail in the sprite list area, located on the lower-right portion of the Scratch interface.
In addition to a thumbnail, Scratch also displays the name of each sprite as well as the number of scripts and costumes belonging to each sprite. To work with a sprite and edit its scripts, costumes, and sound effects, just click on its thumbnail. The currently selected sprite is highlighted by a blue outline. View Modes and Presentation Button
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Pressing the view buttons, allows you to change the arrangement of the user interface. The first button increases the size of the script area to allow you more space to work on your scripts. The second button increases the size of the stage so that you can focus on placement of sprites and the design of your application.
If you click on the Presentation Mode button, located above the top-right corner of the stage, you can run your Scratch application in Presentation mode. Presentation mode displays your application in full screen. To exit presentation mode, press the escape key on your keyboard or the exit arrow, located in the top left hand corner of presentation mode. Script Area
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The scripts area consists of two major sections. The Current Sprite Info
section, located at the top of the scripts area, displays information about the currently selected sprite. The rest of the scripts area is controlled by three tabs, which allow you to add scripts, costumes, and sounds to sprites. The scripts tab is where you build your scripts. Scripts are the code that control your program. Scripts are made by dragging code blocks from the blocks palette into the script area and stacking them together. Like Lego. Click here to learn more about building scripts. The costumes tab is where you can change the appearance of your sprite as an application executes. The sounds tab allows you to add sounds to your application. Just as sprites can have different costumes, you can also assign one or more sounds to them (or to the stage), which can be played during application execution, either as background music or noise or as sound effects during game play. Scratch can play back MP3 files as well as most WAV, AU, and AIF audio files. To view the sound files associated with a sprite or to record or import a new file, select the sprite’s thumbnail in the sprite list and then click on the Sounds tab in the scripts area. Blocks Palette
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The blocks palette is where you find all of the blocks needed to make your scripts. The palette is organized into two sections. The top section contains eight button controls, each of which represents a different category of code block. Each of the buttons is color coded. When you click on a category block at the top of the palette, the bottom part of the palette displays all of the buttons available for that category.
When building your scripts, you simply select the block that you want, drag it into the script area, and then snap it together with another block. Just like Lego. |