Layout


1   package org.joshy.html;
2   
3   import org.joshy.html.box.*;
4   import java.awt.Point  ;
5   import java.awt.Rectangle  ;
6   import org.w3c.dom.Element  ;
7   import org.w3c.dom.Node  ;
8   import org.w3c.dom.NodeList  ;
9   import org.joshy.u;
10  import org.joshy.html.box.Box;
11  
12  public class Layout {
13      public int contents_height;
14  
15  
16      /* ============= layout code =================== */
17  
18      public Box layout(Context c, Element   elem) {
19          //u.p("Layout.layout(): " + elem);
20          Box box = createBox(c,elem);
21          return layoutChildren(c, box);
22      }
23  
24      public Box createBox(Context c, Node   node) {
25          Box box = new Box();
26          box.node = node;
27          return box;
28      }
29  
30      /*
31      // we need to pass the graphics incase we need to grab font info for sizing
32      public Rectangle layoutNode(Context c, Node node) {
33          return new Rectangle(0,0);
34      }
35      */
36  
37      public Box layoutChildren(Context c, Box box) {
38          //u.p("Layout.layoutChildren: " + box);
39  
40          Element   elem = (Element  )box.node;
41  
42          // for each child
43          NodeList   nl = elem.getChildNodes();
44          for(int i=0; i<nl.getLength(); i++) {
45              Node   child = nl.item(i);
46  
47  
48              // get the layout for this child
49              Layout layout = getLayout(child);
50              if(layout == null) { continue; }
51              if(layout instanceof NullLayout) { continue; }
52              if(child.getNodeName().equals("br")) { continue; }
53              if(child.getNodeType() == child.COMMENT_NODE) { continue; }
54  
55              Box child_box = null;
56              if(child.getNodeType() == child.ELEMENT_NODE) {
57                  Element   child_elem = (Element  )child;
58                  // execute the layout and get the return bounds
59                  //u.p("doing element layout: " + layout);
60                  c.parent_box = box;
61                  c.placement_point = new Point  (0,box.height);
62                  child_box = layout.layout(c,child_elem);
63                  //u.p("child box = " + child_box);
64              } else {
65                  //u.p("we have to do an anonymous text block on this: " + child.getNodeValue());
66                  // create anonymous block box
67                  // prepare the node list of the text children
68                  //child_box = new AnonymousBlockBox(child);
69                  // call layout
70                  //u.p("layout = " + layout);
71                  //u.p("doing non element layout: " + layout);
72                  child_box = ((AnonymousBoxLayout)layout).layout(c,elem,child);
73  
74                  // skip text children if the prev_child == anonymous block box
75                  // because that means they were sucked into this block
76                  Node   last_node = ((AnonymousBlockBox)child_box).last_node;
77                  // if anonymous box is only one node wide then skip this
78                  // junk
79                  if(child != last_node) {
80                      while(true) {
81                          i++;
82                          Node   ch = nl.item(i);
83                          //u.p("trying to skip: " + ch);
84                          if(ch == last_node) {
85                              break;
86                          }
87                      }
88                  }
89  
90  
91  
92              }
93              box.addChild(child_box);
94              // set the child_box location
95              child_box.x = 0;
96              child_box.y = box.height;
97  
98              //joshy fix the 'fixed' stuff later
99              // if fixed then don't modify the final layout bounds
100             // because fixed elements are removed from normal flow
101             if(child_box.fixed) {
102                 continue;
103             }
104 
105 
106             // increase the final layout width if the child was greater
107             if(child_box.width > box.width) {
108                 box.width = child_box.width;
109             }
110 
111             // increase the final layout height by the height of the child
112             box.height += child_box.height;
113             //u.p("final extents = " + lt);
114             //u.p("final child box was: " + child_box);
115         }
116         c.addMaxWidth(box.width);
117         return box;
118     }
119 
120 
121 
122     /* ========== painting code ============== */
123     // the core function that implements the recursive layout/paint loop
124     // perhaps we should call it something else?
125     public void paint(Context c, Box box) {
126         //u.p("Layout.paint() " + box);
127         //Point old_cursor = new Point(c.getCursor());
128         //Rectangle contents = layoutChildren(c,elem);
129         //c.cursor = old_cursor;
130         paintBackground(c,box);
131         paintComponent(c,box);
132         paintChildren(c,box);
133         paintBorder(c,box);
134         this.contents_height = box.height;
135     }
136 
137     public void paintBackground(Context c, Box box) { }
138     public void paintComponent(Context c, Box box) { }
139     public void paintBorder(Context c, Box box) { }
140 
141     public void paintChildren(Context c, Box box) {
142         //u.p("Layout.paintChildren(): " + box);
143         //u.p("child count = " + box.boxes.size());
144         for(int i=0; i<box.getChildCount(); i++) {
145             Box child = (Box)box.getChild(i);
146             //u.p("child = " + child);
147             Layout layout = null;
148             if(child.isAnonymous()) {
149                 layout = new InlineLayout();
150             } else {
151                 layout = getLayout(child.node);
152             }
153             paintChild(c,child,layout);
154         }
155     }
156 
157     public void paintChild(Context c, Box box, Layout layout) {
158         layout.paint(c,box);
159     }
160 
161 
162     /* =========== utility code ============= */
163     public Layout getLayout(Node   node) {
164         return LayoutFactory.getLayout(node);
165     }
166 
167     public static String   getPosition(Context c, Box box) {
168         String   position = c.css.getStringProperty(box.node,"position",false);
169         if(position == null) {
170             position = "static";
171         }
172         return position;
173     }
174 
175     public boolean isFixed(Context c, Box box) {
176         if(getPosition(c,box).equals("fixed")) {
177             return true;
178         }
179         return false;
180     }
181 
182 
183     public static boolean isFloated(Box inline, Context c) {
184         return isFloated(inline.node,c);
185     }
186     public static boolean isFloated(Node   node, Context c) {
187         String   float_val = c.css.getStringProperty(node,"float");
188         if(float_val == null) { return false; }
189         if(float_val.equals("left")) { return true; }
190         if(float_val.equals("right")) { return true; }
191         return false;
192     }
193 
194     public boolean isBlockLayout(Element   elem, Context c) {
195         NodeList   children = elem.getChildNodes();
196         for(int i=0; i<children.getLength(); i++) {
197             Node   child = children.item(i);
198             if(isBlockNode(child,c)) {
199                 //u.p("this layout is block");
200                 return true;
201             }
202         }
203         return false;
204     }
205 
206     public static boolean isBlockNode(Node   child, Context c) {
207         if(child instanceof Element  ) {
208             Element   el = (Element  )child;
209             String   display = c.css.getStringProperty(el,"display",false);
210             //u.p("display = " + display);
211             if(display != null && display.equals("block")) {
212                 if(!isFloated(el,c)) {
213                     //u.p(child.getNodeName() + " is a block");
214                     return true;
215                 } else {
216                     //u.p("isBlockNode() found a floated block");
217                 }
218             }
219         }
220         return false;
221     }
222 
223     public static boolean isReplaced(Node   node) {
224         if(node.getNodeName().equals("img")) {
225             return true;
226         }
227         if(node.getNodeName().equals("input")) {
228             return true;
229         }
230 
231         return false;
232     }
233 
234     public static boolean isFloatedBlock(Node   node, Context c) {
235         if(node.getNodeType() != node.ELEMENT_NODE) {
236             return false;
237         }
238 
239         Element   el = (Element  )node;
240         String   display = c.css.getStringProperty(el,"display",false);
241         //u.p("display = " + display);
242         if(display != null && display.equals("block")) {
243             if(isFloated(node,c)) {
244                 //u.p("it's a floated block");
245                 return true;
246             }
247         }
248         return false;
249     }
250 
251 }
252 
253
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