Motorola C450 用户手册

 

• 

public void setViewWindow(int x, int y, int width, 

int height)

 – Sets the portion of the PlayField that will be drawn when 

draw(Graphics, int, int) is called. This will limit the portion of the PlayField that is 
drawn to the rectangle defined by the region 

(x, y)

 to 

(x + width, y + 

height)

. The default view window (at construction time) is the entire area of the 

PlayField, i.e. the rectangular region bounded by 

(0, 0)

 and (getGridWidth() 

* 

getCellWidth()

, 

getGridHeight() 

* getCellHeight())

.The rectangle defined 

by the parameters may extend beyond the bounds of the PlayField. If this happens, 
the 

draw(graphics, int, int)

 method will draw no tiles in the area outside 

the grid boundaries. Sprites may still be drawn in this area if their position places 
them outside the bounds of the PlayField grid. The view window stays in effect until it 

is modified by another call to this method or is reset as a result of calling 
setStaticTileSet(Image, int, int). The method parameters are 

x

 - x coord of top-left 

pixel for the drawing view window, 

y

 - y coord of top-left pixel for the drawing view 

window, 

width

 - width of the drawing view window, and 

height

 - height of the 

drawing view window. 

Using PlayField 

The following is a code sample to show implementation of 

PlayField

: 

// Creates a playField with 100 columns and 10  

// rows and tiles with 24x16 pixels 

PlayField foreground = new PlayField(100, 10, 
Image.createImage("tiles.png"), 24, 16); 

// Sets the first cell in the first line to  

// empty(tile with index 0) 

foreground.setCell(0, 0, 0); 

// Fills the second cell in the first line with tile 1 

foreground.setCell(1, 0, 1); 

// Fills the third cell in the first line with tile 2 

foreground.setCell(2, 0, 2); 

// Fills the fourth cell in the first line with tile 3 

foreground.setCell(3, 0, 3); 

// Gets the Graphics object for this GameScreen 

Graphics g = getGraphics(); 

// Draws the foreground playfield 

foreground.draw(g, 0, 0);