item.java

j2me polish学习的经典代码

					this.border.paint(bX, bY, width, height, g);
				}
			}
		//#endif
		
		// paint label:
		if (this.label != null) {
			if (this.useSingleRow) {
				this.label.paint( x, y, leftBorder, rightBorder - (this.contentWidth + this.paddingHorizontal), g );
				x += this.label.itemWidth;
				leftBorder += this.label.itemWidth;
			} else {
				this.label.paint( x, y, leftBorder, rightBorder, g );
				y += this.label.itemHeight;
			}
		}
		
		leftBorder += (this.marginLeft + this.borderWidth + this.paddingLeft);
		//#ifdef polish.css.before
			leftBorder += this.beforeWidth;
		//#endif
		//System.out.println( this.style.name + ":  increasing leftBorder by " + (this.marginLeft + this.borderWidth + this.paddingLeft));
		rightBorder -= (this.marginRight + this.borderWidth + this.paddingRight);
		//#ifdef polish.css.after
			rightBorder -= this.afterWidth;
		//#endif

		//System.out.println( this.style.name + ":  decreasing rightBorder by " + (this.marginRight + this.borderWidth + this.paddingRight));
		if ( this.isLayoutCenter  && availableWidth > this.itemWidth) {
			int difference = (availableWidth - this.itemWidth) / 2; 
			x += difference;
			if (isLayoutShrink) {
				leftBorder += difference;
				rightBorder -= difference;
				//System.out.println("item " + this + ": (center) shrinking left border to " + leftBorder + ", right border to " + rightBorder);
			}
		} else if ( this.isLayoutRight && availableWidth > this.itemWidth) {
			// adjust the x-position so that the item is painted up to
			// the right border (when it starts at x):
			x += availableWidth - this.itemWidth;
			if (isLayoutShrink) {
				leftBorder += availableWidth - this.itemWidth;
				//System.out.println("item " + this + ": (right) shrinking left border to " + leftBorder);
			}
		} else if (isLayoutShrink && availableWidth > this.itemWidth) {
			rightBorder -= availableWidth - this.itemWidth;
			//System.out.println("item " + this + ": (left) shrinking right border to " + rightBorder);
		}
		
		// paint background:
		x += this.marginLeft;
		y += this.marginTop;
		//#if polish.css.include-label
			if (!this.includeLabel) {
		//#endif
				if (this.background != null) {
					this.background.paint(x, y + this.backgroundYOffset, this.backgroundWidth, this.backgroundHeight, g);
				}
				// paint border:
				if (this.border != null) {
					this.border.paint(x, y + this.backgroundYOffset, this.backgroundWidth, this.backgroundHeight, g);
				}
		//#if polish.css.include-label
			}
		//#endif
		
		x += this.borderWidth + this.paddingLeft;
		y += this.borderWidth + this.paddingTop;
		int originalContentY = y;
		
		// paint before element:
		//#if polish.css.before || polish.css.after || polish.css.min-height  || polish.css.max-height
			boolean isVerticalCenter = (this.layout & LAYOUT_VCENTER) == LAYOUT_VCENTER; 
			boolean isTop = !isVerticalCenter && (this.layout & LAYOUT_TOP) == LAYOUT_TOP; 
			boolean isBottom = !isVerticalCenter && (this.layout & LAYOUT_BOTTOM) == LAYOUT_BOTTOM; 
		//#endif
		//#if polish.css.min-height
			if (this.minimumHeight != 0) {
				int minHeight = this.minimumHeight - ( 2 * this.borderWidth + this.marginTop + this.marginBottom + this.paddingTop + this.paddingBottom);
				if ( isVerticalCenter ) {
//					System.out.println("vertical: adjusting contY by " + ((this.minimumHeight - this.contentHeight) / 2)
//							+ ", contentHeight=" + this.contentHeight + ", minHeight=" + this.minimumHeight );
					y += (minHeight - this.contentHeight) / 2; 
				} else if ( isBottom ) {
					//System.out.println("bottom: adjusting contY by " + (this.minimumHeight - this.contentHeight) );
					y += (minHeight - this.contentHeight);
				}
			}
		//#endif
		//#ifdef polish.css.before
			if (this.beforeImage != null) {
				int beforeY = y;
				int yAdjustment = this.beforeHeight - this.contentHeight;
				if ( this.beforeHeight < this.contentHeight) {
					if (isTop) {
						beforeY -= yAdjustment;
					} else if (isBottom) {
						beforeY += yAdjustment;
					} else {
						beforeY -= yAdjustment / 2;
					}
				} else {
					if (isTop) {
						// keep contY
					} else if (isBottom) {
						y += yAdjustment;
					} else {
						y += yAdjustment / 2;
					}
					//contY += (this.beforeHeight - this.contentHeight) / 2;
				}
				g.drawImage(this.beforeImage, x, beforeY, Graphics.TOP | Graphics.LEFT );
				x += this.beforeWidth;
			}
		//#endif
		
		// paint after element:
		//#ifdef polish.css.after
			if (this.afterImage != null) {
				int afterY = originalContentY;
				int yAdjustment = this.afterHeight - this.contentHeight;
				if ( this.afterHeight < this.contentHeight) {
					if (isTop) {
						afterY -= yAdjustment;
					} else if (isBottom) {
						afterY += yAdjustment;
					} else {
						afterY -= yAdjustment / 2;
					}
					//afterY += (this.contentHeight - this.afterHeight) / 2;
				} else {
					//#ifdef polish.css.before
					if (this.afterHeight > this.beforeHeight) {
					//#endif
						if (isTop) {
							// keep contY
						} else if (isBottom) {
							y = originalContentY + yAdjustment;
						} else {
							y = originalContentY + yAdjustment / 2;
						}
						//contY = originalContentY + (this.afterHeight - this.contentHeight) / 2;
					//#ifdef polish.css.before
					}
					//#endif
				}
				g.drawImage(this.afterImage, rightBorder, afterY, Graphics.TOP | Graphics.LEFT );
			}
		//#endif
		

		// paint content:
		this.contentX = x;
		this.contentY = y;
		paintContent( x, y, leftBorder, rightBorder, g );				
	}
	
	/**
	 * Initialises this item.
	 * 
	 * @param firstLineWidth the maximum width of the first line 
	 * @param lineWidth the maximum width of any following lines
	 */
	protected void init( int firstLineWidth, int lineWidth ) {
		//#debug
		System.out.println("intialising item " + this.getClass().getName() + " (" + this + ")");
		if (this.style != null && !this.isStyleInitialised) {
			setStyle( this.style );
		}
		//#ifdef polish.useDynamicStyles
			else if (this.style == null) {
				initStyle();
			}
		//#else
			else if (this.style == null && !this.isStyleInitialised) {
				//#debug
				System.out.println("Setting default style for item " + getClass().getName() );
				setStyle( StyleSheet.defaultStyle );
			}
		//#endif
		int labelWidth = 0;
		int labelHeight = 0;
		if (this.label != null) {
			if (!this.label.isInitialised) {
				this.label.init( firstLineWidth, lineWidth );
			}
			labelWidth = this.label.itemWidth;
			labelHeight = this.label.itemHeight;
		}
		// calculate content width and content height:
		int noneContentWidth =  
			 	this.marginLeft + this.borderWidth + this.paddingLeft 
				+ this.paddingRight + this.borderWidth + this.marginRight;
		//#ifdef polish.css.before
			noneContentWidth += this.beforeWidth;
		//#endif
		//#ifdef polish.css.after
			noneContentWidth += this.afterWidth;
		//#endif
		/*
		if (noneContentWidth >= firstLineWidth) {
			System.out.println("INVALID NONE CONTENT WIDTH=" + noneContentWidth);
		}
		*/
		//#ifdef polish.css.max-width
			int firstLineAdjustedWidth = firstLineWidth;
			int lineAdjustedWidth = lineWidth;
			if (this.maximumWidth != 0 ) {
				if (firstLineAdjustedWidth > this.maximumWidth ) {
					firstLineAdjustedWidth = this.maximumWidth;
				} 
				if (lineAdjustedWidth > this.maximumWidth ) {
					lineAdjustedWidth = this.maximumWidth;
				}
			}
			int firstLineContentWidth = firstLineAdjustedWidth - noneContentWidth;
			int availableContentWidth = lineAdjustedWidth - noneContentWidth;
		//#else
			//# int firstLineContentWidth = firstLineWidth - noneContentWidth;
			//# int availableContentWidth = lineWidth - noneContentWidth;
		//#endif
		// initialise content by subclass:
		initContent( firstLineContentWidth, availableContentWidth );
		if (this.contentWidth == 0 && this.contentHeight == 0) {
			this.itemWidth = labelWidth;
			this.itemHeight = labelHeight;
			this.backgroundHeight = 0;
			this.backgroundWidth = 0;
			this.isInitialised = true;
			return;
		}
		this.itemWidth = noneContentWidth + this.contentWidth;
		//#ifdef polish.css.min-width
		if (this.itemWidth < this.minimumWidth ) {
			this.itemWidth = this.minimumWidth;
		}
		//#endif
		int cHeight = this.contentHeight;
		//#ifdef polish.css.before
			if (this.contentHeight < this.beforeHeight) {
				cHeight = this.beforeHeight;
			}
		//#endif
		//#ifdef polish.css.after
			if (this.contentHeight < this.afterHeight) {
				cHeight = this.afterHeight;
			}
		//#endif
		int noneContentHeight = this.marginTop + this.borderWidth + this.paddingTop 
			  + this.paddingBottom + this.borderWidth + this.marginBottom;
		if (this.itemWidth + labelWidth <= lineWidth) {
			// label and content fit on one row:
			this.itemWidth += labelWidth;
			this.useSingleRow = true;
			if (this.label != null) {
				if ( (this.label.layout & LAYOUT_NEWLINE_AFTER) != 0 || ((this.layout & LAYOUT_NEWLINE_BEFORE) == LAYOUT_NEWLINE_BEFORE )) {
					this.useSingleRow = false;
					cHeight += labelHeight;
				}
			}
			if ( cHeight + noneContentHeight < labelHeight ) {
				cHeight = labelHeight - noneContentHeight;
			}
		} else {
			this.useSingleRow = false;
			cHeight += labelHeight;
		}
		if ( this.isLayoutExpand ) {
			this.itemWidth = lineWidth;
			//#ifdef polish.css.max-width
				if (this.maximumWidth != 0 && lineWidth > this.maximumWidth ) {
					this.itemWidth = this.maximumWidth;
				}
			//#endif
		} else if (this.itemWidth > lineWidth) {
			this.itemWidth = lineWidth;
		}
		if (cHeight + noneContentHeight < this.minimumHeight) {
			cHeight = this.minimumHeight - noneContentHeight;
		}
		//#if polish.css.max-height
			if (this.maximumHeight != 0 && cHeight + noneContentHeight > this.maximumHeight) {
				cHeight = this.maximumHeight - noneContentHeight;
			}
		//#endif
		this.itemHeight = cHeight + noneContentHeight;
		if (this.useSingleRow) {
			this.backgroundWidth = this.itemWidth - this.marginLeft - this.marginRight - labelWidth;
			this.backgroundHeight = cHeight
							  + noneContentHeight
							  - this.marginTop
							  - this.marginBottom;
		} else {
			this.backgroundWidth = this.itemWidth - this.marginLeft - this.marginRight;
			this.backgroundHeight = cHeight
							  + noneContentHeight
							  - this.marginTop
							  - this.marginBottom
							  - labelHeight;
		}
		this.isInitialised = true;
		//#debug
		System.out.println("Item.init(): contentWidth=" + this.contentWidth + ", itemWidth=" + this.itemWidth + ", backgroundWidth=" + this.backgroundWidth);
	}
	
	//#ifdef polish.useDynamicStyles
	/**
	 * Initialises the appropriate style for this item.
	 */
	protected void initStyle() {
		//System.out.println("item [" + this.getClass().getName() + "/" + this.cssSelector + "/" + this.hashCode() + "] has been initalised: " + this.isStyleInitialised );
		if (this.screen == null) {
			if (this.parent != null) {
				this.screen = getScreen();
			} else {
				this.screen = StyleSheet.currentScreen;
			}
		}
		if (this.style == null) {
			this.cssSelector = createCssSelector();
			//#debug
			System.out.println("getting style for item [" + this.cssSelector + "].");
			setStyle( StyleSheet.getStyle( this ) );
		} else {
			//System.out.println("item has already style [" + this.style.name + "].");
			this.cssSelector = this.style.name;
		}
		this.isStyleInitialised = true;
	}
	//#endif
	

	/**
	 * Initialises this item. 
	 * The implementation needs to calculate and set the contentWidth and 
	 * contentHeight fields. 
	 * The implementation should take the fields preferredWidth and preferredHeight
	 * into account.
	 * 
	 * 
	 * @param firstLineWidth the maximum width of the first line 
	 * @param lineWidth the maximum width of any following lines
	 * @see #contentWidth
	 * @see #contentHeight
	 * @see #preferredWidth
	 * @see #preferredHeight
	 */
	protected abstract void initContent(int firstLineWidth, int lineWidth);
	
	
	/**
	 * Paints the content of this item.
	 * The background has already been painted and the border will be added after
	 * this method returns.
	 * 
	 * @param x the left start position
	 * @param y the upper start position
	 * @param leftBorder the left border, nothing must be painted left of this position
	 * @param rightBorder the right border, nothing must be painted right of this position
	 * @param g the Graphics on which this item should be painted.
	 */
	protected abstract void paintContent( int x, int y, int leftBorder, int rightBorder, Graphics g );
	
	//#ifdef polish.useDynamicStyles	
	/**
	 * Retrieves the CSS selector for this item.
	 * The CSS selector is used for the dyn