From: adam <adam@megacz.com>
Date: Thu, 8 Apr 2004 02:34:34 +0000 (+0000)
Subject: Massive improvement in Simplex layout solver
X-Git-Tag: RC4~27
X-Git-Url: http://git.megacz.com/?p=org.ibex.core.git;a=commitdiff_plain;h=b1568b13f53ca805911fcd7737daf79492d6be1f

Massive improvement in Simplex layout solver

darcs-hash:20040408023434-5007d-4db3e0e4c7d1602bd9509357ddd40fe7b7f4636d.gz
---

diff --git a/src/org/ibex/Box.java b/src/org/ibex/Box.java
index c2f16dc..e3e30ec 100644
--- a/src/org/ibex/Box.java
+++ b/src/org/ibex/Box.java
@@ -1,5 +1,5 @@
 // FIXME
-// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
+// Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
 package org.ibex;
 
 // FEATURE: reflow before allowing js to read from width/height 
@@ -56,8 +56,6 @@ public final class Box extends JSScope implements Scheduler.Task {
     //#define CHECKSET_BOOLEAN(prop) boolean nu = toBoolean(value); if (nu == prop) break; prop = nu;
     //#define CHECKSET_STRING(prop) if ((value==null&&prop==null)||(value!=null&&value.equals(prop))) break; prop=(String)value;
 
-    void mark_for_repack() { MARK_REPACK; }
-
     protected Box() { super(null); }
 
     static Hash boxToCursor = new Hash(500, 3);
@@ -187,9 +185,6 @@ public final class Box extends JSScope implements Scheduler.Task {
         dirty();
     }
 
-    public Box getRoot() { return parent == null ? this : parent.getRoot(); }
-    public Surface getSurface() { return Surface.fromBox(getRoot()); }
-
     // FEATURE: use cx2/cy2 format
     /** Adds the intersection of (x,y,w,h) and the node's current actual geometry to the Surface's dirty list */
     public void dirty() { dirty(0, 0, width, height); }
@@ -212,84 +207,46 @@ public final class Box extends JSScope implements Scheduler.Task {
 
     // Reflow ////////////////////////////////////////////////////////////////////////////////////////
 
-    Box nextPackedSibling() { Box b = nextSibling(); return b == null || (b.test(PACKED | VISIBLE)) ? b : b.nextPackedSibling(); }
-    Box firstPackedChild() { Box b = getChild(0); return b == null || (b.test(PACKED | VISIBLE)) ? b : b.nextPackedSibling(); }
-
-    private static Box[] frontier = new Box[65535];
-    private static int[] frontier_content = new int[65535];
+    // worst case runtime = O(numboxes * numboxes_in_widest_row)
+    
+    private static Box[] frontier = new Box[65535];  // FIXME: GC hazard
 
     /** pack the boxes into rows and columns; also computes contentwidth */
-    void repack() {
-        for(Box child = getChild(0); child != null; child = child.nextSibling()) child.repack();
-        contentwidth = 0;
-        contentheight = 0;
-        if (treeSize() == 0) { constrain(); return; }
-        //#repeat COLS/ROWS rows/cols cols/rows col/row row/col colspan/rowspan rowspan/colspan contentheight/contentwidth contentwidth/contentheight
-        if (test(FIXED) == COLS) {
-            int childnum = 0;
-            Box lastpacked = null;
-            int maxfront = 0;
-            int maxrow = 0;
-            int rowwidth = 0;
-            for(Box child = getChild(0); child != null; child = child.nextSibling(), childnum++) {
-                if (!(child.test(PACKED) && child.test(VISIBLE))) continue;
-                int col = lastpacked == null ? 0 : (lastpacked.col + lastpacked.colspan);
-                int row = lastpacked == null ? 0 : lastpacked.row;
-                int colspan = min(cols, child.colspan);
-                for(int i=0; i<maxfront; i++) {
-                    if (col + colspan > cols) {
-                        row++;
-                        for(; i>0; i--) row = max(row, frontier[i].row + frontier[i].rowspan);
-                        col = 0;
-                        rowwidth = 0;
-                        continue;
-                    }
-                    Box front = frontier[i];       // FIXME: O(nlgn)
-                    if (front.row + front.rowspan <= row) {
-                        frontier[i] = frontier[maxfront-1];
-                        frontier_content[i] = frontier_content[maxfront-1];
-                        maxfront--;
-                        frontier[maxfront] = null;
-                        frontier_content[maxfront] = 0;
-                        i--;
-                        continue;
-                    }
-                    if ((front.col <= col && front.col + front.colspan > col) ||
-                        (front.col < (col+colspan) && front.col + front.colspan >= (col+colspan))) {
-                        col = front.col + front.colspan;
-                        rowwidth += front.contentwidth; // FIXME: suspect
+    void pack() {
+        for(Box child = getChild(0); child != null; child = child.nextSibling()) child.pack();
+        int frontier_size = 0; contentwidth = 0; contentheight = 0;
+        //#repeat COLS/ROWS rows/cols cols/rows col/row row/col colspan/rowspan rowspan/colspan \
+        //        contentheight/contentwidth contentwidth/contentheight
+        if (treeSize() > 0 && test(FIXED) == COLS) {
+            rows = 0;
+            for(Box child = getChild(0); child != null; child = child.nextSibling()) {
+                if (!child.test(PACKED) || !child.test(VISIBLE)) continue;
+                child.col = (short)(frontier_size <= 0 ? 0 : (frontier[frontier_size-1].col + frontier[frontier_size-1].colspan));
+                child.row = (short)(frontier_size <= 0 ? 0 : frontier[frontier_size-1].row);
+                if (child.col + min(cols,child.colspan) > cols) { child.col = 0; child.row++; }
+                for(int i=0; i<frontier_size; i++)
+                    if (frontier[i].row + frontier[i].rowspan <= child.row) {
+                        frontier[i--] = frontier[--frontier_size]; frontier[frontier_size] = null;
+                    } else if (frontier[i].col<child.col+min(cols,child.colspan)&&frontier[i].col+frontier[i].colspan>child.col) {
+                        child.col = (short)(frontier[i].col + frontier[i].colspan);
+                        if (child.col + min(cols,child.colspan) > cols) {
+                            child.row = (short)(frontier[i].row + frontier[i].rowspan);
+                            for(i--; i>0; i--) child.row = (short)min(row, frontier[i].row + frontier[i].rowspan);
+                            child.col = (short)0;
+                        }
                         i = -1;
-                        continue;
-                    }
-                    break;
-                }
-                child.col = (short)col;
-                child.row = (short)row;
-                maxrow = max(maxrow, child.row + child.rowspan);
-                contentwidth = max(contentwidth, rowwidth);
-                rowwidth = 0;
-                lastpacked = child;
-                for(int i=0; i<maxfront; i++) {
-                    frontier_content[maxfront] =
-                        max(frontier_content[maxfront], frontier_content[i] + child.contentheight);
-                    contentheight = 
-                        max(contentheight, frontier_content[i] + child.contentheight);
-                }
-                frontier[maxfront++] = child;
+                    } else break;
+                frontier[frontier_size++] = child;
             }
-            rows = (short)maxrow;
-            for(int i=0; i<maxfront; i++) frontier[i] = null;
-            for(int i=0; i<maxfront; i++) frontier_content[i] = 0;
+            for(int i=0; i<frontier_size; i++){rows=(short)max(rows, frontier[i].row + frontier[i].rowspan); frontier[i] = null; }
         }
         //#end
-        constrain();
-    }
-
-    void constrain() {
+        solve(true);
         //#repeat contentwidth/contentheight contentheight/contentwidth minwidth/minheight row/col col/row \
         //        textwidth/textheight maxwidth/maxheight cols/rows rows/cols colspan/rowspan rowspan/colspan
         contentwidth = bound(minwidth,
-                             max(contentwidth, font == null || text == null ? 0 : font.textwidth(text)),
+                             max(contentwidth,
+                                 font == null || text == null ? 0 : font.textwidth(text)),
                              maxwidth);
         //#end
     }
@@ -297,19 +254,12 @@ public final class Box extends JSScope implements Scheduler.Task {
     void resize(LENGTH x, LENGTH y, LENGTH width, LENGTH height) {
         if (x != this.x || y != this.y || width != this.width || height != this.height) {
             boolean sizechange = (this.width != width || this.height != height) && getTrap("SizeChange") != null;
-            boolean poschange = (this.x != x || this.y != y) && getTrap("PosChange") != null;
-            //do {
+            do {
                 int thisx = parent == null ? 0 : this.x;
                 int thisy = parent == null ? 0 : this.y;
-
-                // we can't reenable this until we track
-                // surface-relative sizes; imagine the case of a clear
-                // surface with nonclear children
-
-                /*
-                if (texture == null && (text == null || text.equals(""))) {
+                // we can't reenable this until we track surface-relative sizes; imagine clear surface with nonclear children
+                if (false /*texture == null && (text == null || text.equals(""))*/) {
                     if ((fillcolor & 0xff000000) == 0) break;
-                    // FEATURE: more optimizations here
                     if (this.x == x && this.y == y) {
                         Box who = (parent == null ? this : parent);
                         who.dirty(thisx+min(this.width,width), thisy, Math.abs(width-this.width), max(this.height, height));
@@ -317,83 +267,78 @@ public final class Box extends JSScope implements Scheduler.Task {
                         break;
                     }
                 }
-                */
                 (parent == null ? this : parent).dirty(thisx, thisy, this.width, this.height);
                 this.width = width; this.height = height; this.x = x; this.y = y;
                 dirty();
-                //} while (false);
-                //this.width = width; this.height = height; this.x = x; this.y = y;
+            } while (false);
+            this.width = width; this.height = height; this.x = x; this.y = y;
             if (sizechange) putAndTriggerTrapsAndCatchExceptions("SizeChange", T);
-            if (poschange)  putAndTriggerTrapsAndCatchExceptions("PosChange", T);
         }
     }
 
     private static float[] coeff = null;
-    private static LinearProgramming.Simplex lp_h = new LinearProgramming.Simplex(100, 100, 300);
-    private static LinearProgramming.Simplex lp = new LinearProgramming.Simplex(100, 100, 300);
+    private static Simplex lp_h = new Simplex(100, 100, 300);
+    private static Simplex lp = new Simplex(100, 100, 300);
+
+    // FIXME: numboxes^2, and damn ugly to boot
     private static int[] regions = new int[65535];
     private static int[] regions_v = new int[65535];
+    private static int numregions = 0;
+    private static int numregions_v = 0;
+    //#repeat col/row colspan/rowspan contentwidth/contentheight width/height HSHRINK/VSHRINK numregions/numregions_v \
+    //        maxwidth/maxheight cols/rows minwidth/minheight lp_h/lp lp_h/lp easy_width/easy_height regions/regions_v \
+    //        computeRegions/computeRegions_v
+    private void computeRegions() {
+        numregions = 0;
+        for(Box c = firstPackedChild(); c != null; c = c.nextPackedSibling()) {
+            int target = c.col;
+            for(boolean stop = false;;) {
+                for(int i=0; i<=numregions; i++) {
+                    if (i == numregions) { regions[numregions++] = target; break; }
+                    if (target == regions[i]) break;
+                    if (target < regions[i]) { int tmp = target; target = regions[i]; regions[i] = tmp; }
+                }
+                if (stop) break;
+                stop = true;
+                target = min(cols, c.col+c.colspan);
+            }
+        }
+        if (regions[numregions-1] == cols) numregions--;
+        else regions[numregions] = cols;
+    }
+    //#end
 
-    void place_children() {
+    void solve(boolean findMinimum) {
         int numkids = 0; for(Box c = firstPackedChild(); c != null; c = c.nextPackedSibling()) numkids++;
-        int numregions = 0, numregions_v = 0;
         //#repeat col/row colspan/rowspan contentwidth/contentheight width/height HSHRINK/VSHRINK numregions/numregions_v \
-        //        maxwidth/maxheight cols/rows minwidth/minheight lp_h/lp lp_h/lp easy_width/easy_height regions/regions_v
+        //        maxwidth/maxheight cols/rows minwidth/minheight lp_h/lp lp_h/lp easy_width/easy_height regions/regions_v \
+        //        computeRegions/computeRegions_v
         if (numkids > 0 && cols > 1) do {
-            // FIXME: numboxes^2, and damn ugly to boot
-            for(Box c = firstPackedChild(); c != null; c = c.nextPackedSibling()) {
-                int target = c.col;
-                for(boolean stop = false;;) {
-                    for(int i=0; i<=numregions; i++) {
-                        if (i == numregions) { regions[numregions++] = target; break; }
-                        if (target == regions[i]) break;
-                        if (target < regions[i]) { int tmp = target; target = regions[i]; regions[i] = tmp; }
-                    }
-                    if (stop) break;
-                    stop = true;
-                    target = min(cols, c.col+c.colspan);
-                }
-            }
-            if (regions[numregions-1] == cols) numregions--;
-            else regions[numregions] = cols;
-
-            /* boolean easy_width = contentwidth >= width; */
-            /*
-            for(Box c = firstPackedChild(); easy_width && c != null; c = c.nextPackedSibling()) {
-                if (c.contentwidth == c.maxwidth) continue;
-                if (c.maxwidth == Integer.MAX_VALUE) continue;
-                easy_width = false;
-            }
-            if (easy_width) for(int i=0; i<cols; i++) {
-                easy_width = false;
-                boolean good = true;
-                for(Box c = firstPackedChild(); good && c != null; c = c.nextPackedSibling())
-                    if (c.col <= i && c.col + c.colspan > i && c.maxwidth < Integer.MAX_VALUE)
-                        good = false;
-                if (good) { easy_width = true; break; }
-            }
-            if (easy_width) break;
-            */
-            int nc = numregions * 2 + numkids + 1;
+            computeRegions();
+            int nc = numregions * 3 + numkids * 2 + 3;
             if (coeff == null || nc+1>coeff.length) coeff = new float[nc+1];
             lp_h.init(nc);
 
             for(int i=0; i<coeff.length; i++) coeff[i] = (float)0.0;
-            coeff[numregions*2+numkids] = (float)10000.0;               // priority 1: sum of columns no greater than parent
-            for(int i=numregions*2; i<numregions*2+numkids; i++) coeff[i] = (float)100.0;  // priority 2: honor maxwidths
-            for(int i=numregions; i<numregions*2; i++) coeff[i] = (float)(0.1);            // priority 3: equalize columns
+            if (!findMinimum) {
+                coeff[numregions*2+numkids] = (float)10000.0;               // priority 1: sum of columns no greater than parent
+                for(int i=numregions*2; i<numregions*2+numkids; i++) coeff[i] = (float)100.0;  // priority 2: honor maxwidths
+                for(int i=numregions; i<numregions*2; i++) coeff[i] = (float)(0.1);            // priority 3: equalize columns
+            } else {
+                coeff[numregions*2+numkids] = (float)1.0;
+            }
             lp_h.setObjective(coeff, false);
-            
-            for(int i=0; i<numregions; i++) lp_h.set_lowbo(i+1, (float)0.0); // invariant: columns cannot have negative size
 
-            // invariant: columns must be at least as large as parent
-            for(int i=0; i<coeff.length; i++) coeff[i] = (i<numregions) ? (float)(regions[i+1] - regions[i]) : (float)0.0;
-            lp_h.add_constraint(coeff, LinearProgramming.GE, (float)width);
+            for(int i=0; i<numregions; i++) {
+                for(int j=0; j<coeff.length; j++) coeff[j] = j==i ? (float)1.0 : (float)0.0;
+                lp_h.add_constraint(coeff, Simplex.GE, (float)0.0);
+            }
 
             // priority 1: sum of columns as close to parent's width as possible
             for(int i=0; i<coeff.length; i++) coeff[i] = (i<numregions) ? (float)(regions[i+1] - regions[i]) : (float)0.0;
             coeff[numregions*2+numkids] = (float)-1.0;
-            lp_h.add_constraint(coeff, LinearProgramming.EQ, (float)width);
+            if (!findMinimum) lp_h.add_constraint(coeff, Simplex.LE, (float)width);
+            else              lp_h.add_constraint(coeff, Simplex.LE, (float)0);
 
             int childnum = 0;
             for(Box child = firstPackedChild(); child != null; child = child.nextPackedSibling()) {
@@ -403,59 +348,52 @@ public final class Box extends JSScope implements Scheduler.Task {
                 for(int r=0; r<numregions; r++)
                     if (regions[r] >= child.col && regions[r+1] <= min(child.col+child.colspan,cols))
                         coeff[r] = (float)(regions[r+1] - regions[r]);
-                lp_h.add_constraint(coeff, LinearProgramming.GE, (float)child.contentwidth);
-
-                // priority 2: honor maxwidths
-                int child_maxwidth = child.test(HSHRINK) ? min(child.maxwidth, child.contentwidth) : child.maxwidth;
-                if (child_maxwidth < Integer.MAX_VALUE) {
-                    for(int i=0; i<coeff.length; i++) coeff[i] = (float)0.0;
-                    for(int r=0; r<numregions; r++)
-                        if (regions[r] >= child.col && regions[r+1] <= min(child.col+child.colspan,cols))
-                            coeff[r] = (float)(regions[r+1] - regions[r]);
-                    coeff[numregions*2+childnum] = (float)-1.0;
-                    lp_h.add_constraint(coeff, LinearProgramming.LE, (float)child_maxwidth);
+                lp_h.add_constraint(coeff, Simplex.GE, (float)child.contentwidth);
+                if (!findMinimum) {
+                    // priority 2: honor maxwidths
+                    int child_maxwidth = child.test(HSHRINK) ? min(child.maxwidth, child.contentwidth) : child.maxwidth;
+                    if (child_maxwidth < Integer.MAX_VALUE) {
+                        for(int i=0; i<coeff.length; i++) coeff[i] = (float)0.0;
+                        for(int r=0; r<numregions; r++)
+                            if (regions[r] >= child.col && regions[r+1] <= min(child.col+child.colspan,cols))
+                                coeff[r] = (float)(regions[r+1] - regions[r]);
+                        coeff[numregions*2+childnum] = (float)-1.0;
+                        lp_h.add_constraint(coeff, Simplex.LE, (float)child_maxwidth);
+                    }
                 }
-
                 childnum++;
             }
 
-            // priority 3: equalize columns
-            float avg = ((float)width)/((float)numregions);
-            for(int r=0; r<numregions; r++) {
-                float weight = (float)(regions[r+1] - regions[r]);
-                for(int k=0; k<coeff.length; k++) coeff[k] = (float)(k==r?weight:k==(numregions+r)?-1.0:0.0);
-                lp_h.add_constraint(coeff, LinearProgramming.LE, avg * weight);
-                for(int k=0; k<coeff.length; k++) coeff[k] = (float)(k==r?weight:k==(numregions+r)?1.0:0.0);
-                lp_h.add_constraint(coeff, LinearProgramming.GE, avg * weight);
+            if (!findMinimum) {
+                // priority 3: equalize columns
+                float avg = ((float)width)/((float)numregions);
+                for(int r=0; r<numregions; r++) {
+                    float weight = (float)(regions[r+1] - regions[r]);
+                    for(int k=0; k<coeff.length; k++) coeff[k] = (float)(k==r?weight:k==(numregions+r)?-1.0:0.0);
+                    lp_h.add_constraint(coeff, Simplex.LE, avg * weight);
+                    for(int k=0; k<coeff.length; k++) coeff[k] = (float)(k==r?weight:k==(numregions+r)?1.0:0.0);
+                    lp_h.add_constraint(coeff, Simplex.GE, avg * weight);
+                }
             }
 
-            try {
-                int result = lp_h.solve();
-                switch(result) {
-                    case LinearProgramming.UNBOUNDED:
-                        Log.warn(this, "simplex solver claims unboundedness; this should never happen");
-                        break;
-                    case LinearProgramming.INFEASIBLE:
-                        Log.debug(this, "simplex solver claims infeasibility; this should never happen");
-                        break;
-                    case LinearProgramming.MILP_FAIL:
-                        Log.warn(this, "simplex solver claims MILP_FAIL; this should never happen");
-                        break;
-                    case LinearProgramming.RUNNING:
-                        Log.warn(this, "simplex solver still RUNNING; this should never happen");
-                        break;
-                    case LinearProgramming.FAILURE:
-                        Log.warn(this, "simplex solver claims FAILURE; this should never happen");
-                        break;
-                }
-            } catch (Error e) {
+            try { switch(lp_h.solve()) {
+                case Simplex.UNBOUNDED: Log.warn(this, "simplex claims unboundedness; this should never happen"); break;
+                case Simplex.INFEASIBLE: Log.debug(this, "simplex claims infeasibility; this should never happen"); break;
+                case Simplex.MILP_FAIL: Log.warn(this, "simplex claims MILP_FAIL; this should never happen"); break;
+                case Simplex.RUNNING: Log.warn(this, "simplex still RUNNING; this should never happen"); break;
+                case Simplex.FAILURE: Log.warn(this, "simplex claims FAILURE; this should never happen"); break;
+            } } catch (Error e) {
                 Log.warn(this, "got an Error in simplex solver; not sure why this happens");
                 return;
             }
 
+            if (findMinimum) contentwidth = Math.round(lp_h.solution[lp_h.rows + (2*numregions + numkids + 1)]);
         } while(false);
         //#end
-        
+    }
+
+    void place() {
+        solve(false);
         for(Box child = getChild(0); child != null; child = child.nextSibling()) {
             if (!child.test(VISIBLE)) continue;
             int child_width, child_height, child_x, child_y;
@@ -472,24 +410,19 @@ public final class Box extends JSScope implements Scheduler.Task {
                 int diff;
                 //#repeat col/row colspan/rowspan contentwidth/contentheight width/height colMaxWidth/rowMaxHeight \
                 //        child_x/child_y x/y HSHRINK/VSHRINK maxwidth/maxheight cols/rows minwidth/minheight x_slack/y_slack \
-                //        child_width/child_height ALIGN_RIGHT/ALIGN_BOTTOM ALIGN_LEFT/ALIGN_TOP lp_h/lp easy_width/easy_height \
+                //        child_width/child_height ALIGN_RIGHT/ALIGN_BOTTOM ALIGN_LEFT/ALIGN_TOP lp_h/lp \
                 //        numregions/numregions_v regions/regions_v
                 child_width = 0;
                 child_x = 0;
                 if (cols == 1) {
                     child_x = 0;
                     child_width = width;
-                    /*
-                } else if (easy_width) {
-                    */
                 } else {
-                    for(int r=0; r<numregions; r++) {
-                        if (regions[r] >= child.col && regions[r+1] <= min(child.col+child.colspan,cols)) {
+                    for(int r=0; r<numregions; r++)
+                        if (regions[r] >= child.col && regions[r+1] <= min(child.col+child.colspan,cols))
                             child_width += Math.round(lp_h.solution[lp_h.rows+r+1] * (regions[r+1] - regions[r]));
-                        } else if (regions[r+1] <= child.col) {
+                        else if (regions[r+1] <= child.col)
                             child_x += Math.round(lp_h.solution[lp_h.rows+r+1] * (regions[r+1] - regions[r]));
-                        }
-                    }
                 }
                 diff = (child_width - (child.test(HSHRINK) ? child.contentwidth : min(child_width, child.maxwidth)));
                 child_x += (child.test(ALIGN_RIGHT) ? diff : child.test(ALIGN_LEFT) ? 0 : diff / 2);
@@ -501,7 +434,7 @@ public final class Box extends JSScope implements Scheduler.Task {
 
         for(Box child = getChild(0); child != null; child = child.nextSibling())
             if (child.test(VISIBLE) && child.treeSize() > 0)
-                child.place_children();
+                child.place();
     }
 
 
@@ -547,11 +480,7 @@ public final class Box extends JSScope implements Scheduler.Task {
     
     // Methods to implement org.ibex.js.JS //////////////////////////////////////
 
-    public int globalToLocalX(int x) { return parent == null ? x : parent.globalToLocalX(x - this.x); }
-    public int globalToLocalY(int y) { return parent == null ? y : parent.globalToLocalY(y - this.y); }
-    public int localToGlobalX(int x) { return parent == null ? x : parent.globalToLocalX(x + this.x); }
-    public int localToGlobalY(int y) { return parent == null ? y : parent.globalToLocalY(y + this.y); }
-    
+  
     public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
         switch (nargs) {
             case 1: {
@@ -577,8 +506,6 @@ public final class Box extends JSScope implements Scheduler.Task {
         return super.callMethod(method, a0, a1, a2, rest, nargs);
     }
 
-    public Enumeration keys() { throw new Error("you cannot apply for..in to a " + this.getClass().getName()); }
-
     protected boolean isTrappable(Object key, boolean isRead) {
         if (key == null) return false;
         else if (key instanceof String) {
@@ -657,11 +584,11 @@ public final class Box extends JSScope implements Scheduler.Task {
         }
     }
 
-    void setMaxWidth(Object value) {
+    public void setMaxWidth(Object value) {
         do { CHECKSET_INT(maxwidth); MARK_RESIZE; } while(false);
-        if (parent == null && getSurface() != null) getSurface().pendingWidth = maxwidth;
+        if (parent == null && getSurface() != null) getSurface().pendingWidth = maxwidth; 
     }
-    void setMaxHeight(Object value) {
+    public void setMaxHeight(Object value) {
         do { CHECKSET_INT(maxheight); MARK_RESIZE; } while(false);
         if (parent == null && getSurface() != null) getSurface().pendingHeight = maxheight;
     }
@@ -965,6 +892,17 @@ public final class Box extends JSScope implements Scheduler.Task {
 
     // Trivial Helper Methods (should be inlined) /////////////////////////////////////////
 
+    void mark_for_repack() { MARK_REPACK; }
+    public Enumeration keys() { throw new Error("you cannot apply for..in to a " + this.getClass().getName()); }
+    public Box getRoot() { return parent == null ? this : parent.getRoot(); }
+    public Surface getSurface() { return Surface.fromBox(getRoot()); }
+    Box nextPackedSibling() { Box b = nextSibling(); return b == null || (b.test(PACKED | VISIBLE)) ? b : b.nextPackedSibling(); }
+    Box firstPackedChild() { Box b = getChild(0); return b == null || (b.test(PACKED | VISIBLE)) ? b : b.nextPackedSibling(); }
+    public int globalToLocalX(int x) { return parent == null ? x : parent.globalToLocalX(x - this.x); }
+    public int globalToLocalY(int y) { return parent == null ? y : parent.globalToLocalY(y - this.y); }
+    public int localToGlobalX(int x) { return parent == null ? x : parent.globalToLocalX(x + this.x); }
+    public int localToGlobalY(int y) { return parent == null ? y : parent.globalToLocalY(y + this.y); }
+
     static short min(short a, short b) { if (a<b) return a; else return b; }
     static int min(int a, int b) { if (a<b) return a; else return b; }
     static float min(float a, float b) { if (a<b) return a; else return b; }
diff --git a/src/org/ibex/Surface.java b/src/org/ibex/Surface.java
index e68c392..d2130e3 100644
--- a/src/org/ibex/Surface.java
+++ b/src/org/ibex/Surface.java
@@ -236,7 +236,7 @@ public abstract class Surface extends PixelBuffer implements Scheduler.Task {
         // make sure the root is properly sized
         do {
             abort = false;
-            root.repack();
+            root.pack();
             if (syncRootBoxToSurface) {
                 root.setMaxWidth(JS.N(pendingWidth));
                 root.setMaxHeight(JS.N(pendingHeight));
@@ -248,7 +248,7 @@ public abstract class Surface extends PixelBuffer implements Scheduler.Task {
                 dirty(0, root.maxheight - Main.scarImage.height, Main.scarImage.width, Main.scarImage.height);
             }
             root.resize(root.x, root.y, root.maxwidth, root.maxheight);
-            root.place_children();
+            root.place();
             setSize(root.width, root.height);
             /*String oldcursor = cursor;
             cursor = "default";