Improved layout handler to support trees of nested arrays. Needed for converting and fixing the trade window.

8 files changed, 401 insertions, 199 deletions

diff --git a/src/gui/buy.cpp b/src/gui/buy.cpp
index b95a8b25..bf449b2f 100644
--- a/src/gui/buy.cpp
+++ b/src/gui/buy.cpp
@@ -87,7 +87,6 @@ BuyDialog::BuyDialog():
     place(4, 5, mQuitButton);
     Layout &layout = getLayout();
     layout.setRowHeight(0, Layout::FILL);
-    layout.setColWidth(2, Layout::FILL);
 
     loadWindowState("Buy");
     setLocationRelativeTo(getParent());
diff --git a/src/gui/char_select.cpp b/src/gui/char_select.cpp
index f7042c70..c2306880 100644
--- a/src/gui/char_select.cpp
+++ b/src/gui/char_select.cpp
@@ -100,9 +100,11 @@ CharSelectDialog::CharSelectDialog(LockedArray<LocalPlayer*> *charInfo,
     mNameLabel = new gcn::Label(strprintf(_("Name: %s"), ""));
     mLevelLabel = new gcn::Label(strprintf(_("Level: %d"), 0));
     mMoneyLabel = new gcn::Label(strprintf(_("Money: %d"), 0));
-    mPlayerBox = new PlayerBox();
+    mPlayerBox = new PlayerBox;
+    mPlayerBox->setWidth(74);
 
-    Layout &layout = getLayout();
+    ContainerPlacer place;
+    place = getPlacer(0, 0);
     place(0, 0, mPlayerBox, 1, 5).setPadding(3);
     place(1, 0, mNameLabel, 3);
     place(1, 1, mLevelLabel, 3);
@@ -111,18 +113,12 @@ CharSelectDialog::CharSelectDialog(LockedArray<LocalPlayer*> *charInfo,
     place(2, 3, mNextButton);
     place(1, 4, mNewCharButton);
     place(2, 4, mDelCharButton);
-    layout.setWidth(250);
-    layout.setColWidth(0, 80);
-    layout.setColWidth(3, Layout::FILL);
-    layout.matchColWidth(1, 2);
-    layout.setRowHeight(5, 5);
-    layout.flush();
+    place.getCell().matchColWidth(1, 2);
+    place = getPlacer(0, 1);
     place(0, 0, mUnRegisterButton);
     place(2, 0, mSelectButton);
     place(3, 0, mCancelButton);
-    layout.setColWidth(1, Layout::FILL);
-    reflowLayout();
-    forgetLayout();
+    reflowLayout(250, 0);
 
     setLocationRelativeTo(getParent());
     setVisible(true);
diff --git a/src/gui/login.cpp b/src/gui/login.cpp
index f35f427a..565277a0 100644
--- a/src/gui/login.cpp
+++ b/src/gui/login.cpp
@@ -66,12 +66,10 @@ LoginDialog::LoginDialog(LoginData *loginData):
     place(1, 0, mUserField, 3).setPadding(2);
     place(1, 1, mPassField, 3).setPadding(2);
     place(0, 2, mKeepCheck, 4);
-    place(0, 3, mRegisterButton).setHAlign(Cell::LEFT);
+    place(0, 3, mRegisterButton).setHAlign(LayoutCell::LEFT);
     place(2, 3, mOkButton);
     place(3, 3, mCancelButton);
-    getLayout().setColWidth(1, 20);
-    reflowLayout();
-    forgetLayout();
+    reflowLayout(250, 0);
 
     setLocationRelativeTo(getParent());
     setVisible(true);
diff --git a/src/gui/serverdialog.cpp b/src/gui/serverdialog.cpp
index 70ed7fe8..00490d31 100644
--- a/src/gui/serverdialog.cpp
+++ b/src/gui/serverdialog.cpp
@@ -120,16 +120,12 @@ ServerDialog::ServerDialog(LoginData *loginData):
 
     place(0, 0, serverLabel);
     place(0, 1, portLabel);
-    place(1, 0, mServerNameField, 3).setPadding(3);
-    place(1, 1, mPortField, 3).setPadding(3);
-    place(0, 2, mMostUsedServersDropDown, 4).setPadding(3);
+    place(1, 0, mServerNameField, 3).setPadding(2);
+    place(1, 1, mPortField, 3).setPadding(2);
+    place(0, 2, mMostUsedServersDropDown, 4).setPadding(2);
     place(2, 3, mOkButton);
     place(3, 3, mCancelButton);
-    Layout &layout = getLayout();
-    layout.setWidth(250);
-    layout.setColWidth(1, Layout::FILL);
-    reflowLayout();
-    forgetLayout();
+    reflowLayout(250, 0);
 
     setLocationRelativeTo(getParent());
     setVisible(true);
diff --git a/src/gui/widgets/layout.cpp b/src/gui/widgets/layout.cpp
index 252cf198..2bcc558d 100644
--- a/src/gui/widgets/layout.cpp
+++ b/src/gui/widgets/layout.cpp
@@ -21,9 +21,103 @@
  *  $Id$
  */
 
+#include <cassert>
+
 #include "layout.h"
 
-void Layout::resizeGrid(int w, int h)
+ContainerPlacer ContainerPlacer::at(int x, int y)
+{
+    return ContainerPlacer(mContainer, &mCell->at(x, y));
+}
+
+LayoutCell &ContainerPlacer::operator()
+    (int x, int y, gcn::Widget *wg, int w, int h)
+{
+    mContainer->add(wg);
+    return mCell->place(wg, x, y, w, h);
+}
+
+LayoutCell::~LayoutCell()
+{
+    if (mType == ARRAY) delete mArray;
+}
+
+LayoutArray &LayoutCell::getArray()
+{
+    assert(mType != WIDGET);
+    if (mType == ARRAY) return *mArray;
+    mArray = new LayoutArray;
+    mType = ARRAY;
+    mExtent[0] = 1;
+    mExtent[1] = 1;
+    mPadding = 0;
+    mAlign[0] = FILL;
+    mAlign[1] = FILL;
+    return *mArray;
+}
+
+void LayoutCell::reflow(int nx, int ny, int nw, int nh)
+{
+    assert(mType != NONE);
+    nx += mPadding;
+    ny += mPadding;
+    nw -= 2 * mPadding;
+    nh -= 2 * mPadding;
+    if (mType == ARRAY)
+        mArray->reflow(nx, ny, nw, nh);
+    else
+        mWidget->setDimension(gcn::Rectangle(nx, ny, nw, nh));
+}
+
+void LayoutCell::computeSizes()
+{
+    assert(mType == ARRAY);
+
+    for (std::vector< std::vector< LayoutCell * > >::iterator
+         i = mArray->mCells.begin(), i_end = mArray->mCells.end();
+         i != i_end; ++i)
+    {
+        for (std::vector< LayoutCell * >::iterator
+             j = i->begin(), j_end = i->end(); j != j_end; ++j)
+        {
+            LayoutCell *cell = *j;
+            if (cell && cell->mType == ARRAY) cell->computeSizes();
+        }
+    }
+
+    mSize[0] = mArray->getSize(0);
+    mSize[1] = mArray->getSize(1);
+}
+
+LayoutArray::LayoutArray(): mSpacing(4)
+{
+}
+
+LayoutArray::~LayoutArray()
+{
+    for (std::vector< std::vector< LayoutCell * > >::iterator
+         i = mCells.begin(), i_end = mCells.end(); i != i_end; ++i)
+    {
+        for (std::vector< LayoutCell * >::iterator
+             j = i->begin(), j_end = i->end(); j != j_end; ++j)
+        {
+            delete *j;
+        }
+    }
+}
+
+LayoutCell &LayoutArray::at(int x, int y, int w, int h)
+{
+    resizeGrid(x + w, y + h);
+    LayoutCell *&cell = mCells[y][x];
+    if (!cell)
+    {
+        cell = new LayoutCell;
+    }
+    return *cell;
+}
+
+void LayoutArray::resizeGrid(int w, int h)
 {
     bool extW = w && w > (int)mSizes[0].size(),
          extH = h && h > (int)mSizes[1].size();
@@ -31,127 +125,128 @@ void Layout::resizeGrid(int w, int h)
 
     if (extH)
     {
-        mSizes[1].resize(h, FILL);
+        mSizes[1].resize(h, Layout::FILL);
         mCells.resize(h);
         if (!extW) w = mSizes[0].size();
     }
 
     if (extW)
     {
-        mSizes[0].resize(w, FILL);
+        mSizes[0].resize(w, Layout::FILL);
     }
 
-    for (std::vector< std::vector< Cell > >::iterator
+    for (std::vector< std::vector< LayoutCell * > >::iterator
          i = mCells.begin(), i_end = mCells.end(); i != i_end; ++i)
     {
-        i->resize(w);
+        i->resize(w, NULL);
     }
 }
 
-void Layout::setColWidth(int n, int w)
+void LayoutArray::setColWidth(int n, int w)
 {
     resizeGrid(n + 1, 0);
     mSizes[0][n] = w;
 }
 
-void Layout::setRowHeight(int n, int h)
+void LayoutArray::setRowHeight(int n, int h)
 {
     resizeGrid(0, n + 1);
     mSizes[1][n] = h;
 }
 
-void Layout::matchColWidth(int n1, int n2)
+void LayoutArray::matchColWidth(int n1, int n2)
 {
     resizeGrid(std::max(n1, n2) + 1, 0);
-    std::vector< int > widths = compute(0, mW);
+    std::vector< short > widths = getSizes(0, Layout::FILL);
     int s = std::max(widths[n1], widths[n2]);
     mSizes[0][n1] = s;
     mSizes[0][n2] = s;
 }
 
-Cell &Layout::place(gcn::Widget *widget, int x, int y, int w, int h)
+LayoutCell &LayoutArray::place(gcn::Widget *widget, int x, int y, int w, int h)
 {
-    resizeGrid(x + w, y + h);
-    Cell &cell = mCells[y][x];
+    LayoutCell &cell = at(x, y, w, h);
+    assert(cell.mType == LayoutCell::NONE);
+    cell.mType = LayoutCell::WIDGET;
     cell.mWidget = widget;
+    cell.mSize[0] = w == 1 ? widget->getWidth() : 0;
+    cell.mSize[1] = h == 1 ? widget->getHeight() : 0;
     cell.mExtent[0] = w;
     cell.mExtent[1] = h;
     cell.mPadding = 0;
-    cell.mAlign[0] = Cell::FILL;
-    cell.mAlign[1] = Cell::FILL;
-    int &cs = mSizes[0][x], &rs = mSizes[1][y];
-    if (cs == FILL) cs = 0;
-    if (rs == FILL) rs = 0;
+    cell.mAlign[0] = LayoutCell::FILL;
+    cell.mAlign[1] = LayoutCell::FILL;
+    short &cs = mSizes[0][x], &rs = mSizes[1][y];
+    if (cs == Layout::FILL && w == 1) cs = 0;
+    if (rs == Layout::FILL && h == 1) rs = 0;
     return cell;
 }
 
-void Layout::align(int &pos, int &size, int dim,
-                   Cell const &cell, int *sizes) const
+void LayoutArray::align(int &pos, int &size, int dim,
+                        LayoutCell const &cell, short *sizes) const
 {
-    int size_max = sizes[0] - cell.mPadding * 2;
+    int size_max = sizes[0];
     for (int i = 1; i < cell.mExtent[dim]; ++i)
         size_max += sizes[i] + mSpacing;
-    size = std::min(dim == 0 ? cell.mWidget->getWidth()
-                             : cell.mWidget->getHeight(), size_max);
-    pos += cell.mPadding;
+    size = std::min<int>(cell.mSize[dim], size_max);
 
     switch (cell.mAlign[dim])
     {
-        case Cell::LEFT:
+        case LayoutCell::LEFT:
             return;
-        case Cell::RIGHT:
+        case LayoutCell::RIGHT:
             pos += size_max - size;
             return;
-        case Cell::CENTER:
+        case LayoutCell::CENTER:
             pos += (size_max - size) / 2;
             return;
-        case Cell::FILL:
+        case LayoutCell::FILL:
             size = size_max;
             return;
     }
 }
 
-std::vector< int > Layout::compute(int dim, int upp) const
+std::vector< short > LayoutArray::getSizes(int dim, int upp) const
 {
     int gridW = mSizes[0].size(), gridH = mSizes[1].size();
-    std::vector< int > sizes = mSizes[dim];
+    std::vector< short > sizes = mSizes[dim];
 
     // Compute minimum sizes.
     for (int gridY = 0; gridY < gridH; ++gridY)
     {
         for (int gridX = 0; gridX < gridW; ++gridX)
         {
-            Cell const &cell = mCells[gridY][gridX];
-            if (!cell.mWidget) continue;
+            LayoutCell const *cell = mCells[gridY][gridX];
+            if (!cell || cell->mType == LayoutCell::NONE) continue;
 
-            if (cell.mExtent[dim] == 1)
+            if (cell->mExtent[dim] == 1)
             {
-                int s = dim == 0 ? cell.mWidget->getWidth()
-                                 : cell.mWidget->getHeight();
                 int n = dim == 0 ? gridX : gridY;
-                s += cell.mPadding * 2;
+                int s = cell->mSize[dim] + cell->mPadding * 2;
                 if (s > sizes[n]) sizes[n] = s;
             }
         }
     }
 
+    if (upp == Layout::FILL) return sizes;
+
     // Compute the FILL sizes.
     int nb = sizes.size();
     int nbFill = 0;
     for (int i = 0; i < nb; ++i)
     {
-        if (mSizes[dim][i] == FILL) ++nbFill;
-        if (sizes[i] == FILL) sizes[i] = 0;
+        if (mSizes[dim][i] == Layout::FILL) ++nbFill;
+        if (sizes[i] == Layout::FILL) sizes[i] = 0;
         else upp -= sizes[i];
         upp -= mSpacing;
     }
-    upp = upp + mSpacing - mMargin * 2;
+    upp = upp + mSpacing;
 
     if (nbFill == 0) return sizes;
 
     for (int i = 0; i < nb; ++i)
     {
-        if (mSizes[dim][i] != FILL) continue;
+        if (mSizes[dim][i] != Layout::FILL) continue;
         int s = upp / nbFill;
         sizes[i] += s;
         upp -= s;
@@ -161,43 +256,61 @@ std::vector< int > Layout::compute(int dim, int upp) const
     return sizes;
 }
 
-void Layout::reflow(int &nw, int &nh)
+int LayoutArray::getSize(int dim) const
+{
+    std::vector< short > sizes = getSizes(dim, Layout::FILL);
+    int size = 0;
+    int nb = sizes.size();
+    for (int i = 0; i < nb; ++i)
+    {
+        if (sizes[i] != Layout::FILL) size += sizes[i];
+        size += mSpacing;
+    }
+    return size - mSpacing;
+}
+
+void LayoutArray::reflow(int nx, int ny, int nw, int nh)
 {
     int gridW = mSizes[0].size(), gridH = mSizes[1].size();
 
-    std::vector< int > widths = compute(0, mW);
-    std::vector< int > heights = compute(1, mH);
+    std::vector< short > widths  = getSizes(0, nw);
+    std::vector< short > heights = getSizes(1, nh);
 
-    int x, y = mY + mMargin;
+    int y = ny;
     for (int gridY = 0; gridY < gridH; ++gridY)
     {
-        x = mX + mMargin;
+        int x = nx;
         for (int gridX = 0; gridX < gridW; ++gridX)
         {
-            Cell &cell = mCells[gridY][gridX];
-            if (cell.mWidget)
+            LayoutCell *cell = mCells[gridY][gridX];
+            if (cell && cell->mType != LayoutCell::NONE)
             {
                 int dx = x, dy = y, dw, dh;
-                align(dx, dw, 0, cell, &widths[gridX]);
-                align(dy, dh, 1, cell, &heights[gridY]);
-                cell.mWidget->setDimension(gcn::Rectangle(dx, dy, dw, dh));
+                align(dx, dw, 0, *cell, &widths[gridX]);
+                align(dy, dh, 1, *cell, &heights[gridY]);
+                cell->reflow(dx, dy, dw, dh);
             }
             x += widths[gridX] + mSpacing;
         }
         y += heights[gridY] + mSpacing;
     }
+}
 
-    nw = x - mX - mSpacing + mMargin;
-    nh = y - mY - mSpacing + mMargin;
+Layout::Layout(): mComputed(false)
+{
+    getArray();
+    setPadding(6);
 }
 
-void Layout::flush()
+void Layout::reflow(int &nw, int &nh)
 {
-    int w, h;
-    reflow(w, h);
-    mY += h;
-    mW = w;
-    mSizes[0].clear();
-    mSizes[1].clear();
-    mCells.clear();
+    if (!mComputed)
+    {
+        computeSizes();
+        mComputed = true;
+    }
+
+    nw = nw == 0 ? mSize[0] + 2 * mPadding : nw;
+    nh = nh == 0 ? mSize[1] + 2 * mPadding : nh;
+    LayoutCell::reflow(0, 0, nw, nh);
 }
diff --git a/src/gui/widgets/layout.h b/src/gui/widgets/layout.h
index ae03ed9d..a6e630c2 100644
--- a/src/gui/widgets/layout.h
+++ b/src/gui/widgets/layout.h
@@ -26,172 +26,280 @@
 
 #include <vector>
 
-#include <guichan/widget.hpp>
+#include <guichan/widgets/container.hpp>
+
+class LayoutCell;
 
 /**
- * This class describes the formatting of a widget in the cell of a layout
- * table. Horizontally, a widget can either fill the width of the cell (minus
- * the cell padding), or it can retain its size and be flushed left, or flush
- * right, or centered in the cell. The process is similar for the vertical
- * alignment, except that top is represented by LEFT and bottom by RIGHT.
+ * This class is a helper for adding widgets to nested tables in a window.
  */
-class Cell
+class ContainerPlacer
 {
-    friend class Layout;
-
     public:
 
-        enum Alignment
-        {
-            LEFT, RIGHT, CENTER, FILL
-        };
-
-        Cell(): mWidget(0) {}
+        ContainerPlacer(gcn::Container *c = NULL, LayoutCell *l = NULL):
+            mContainer(c), mCell(l)
+        {}
 
         /**
-         * Sets the padding around the cell content.
+         * Gets the pointed cell.
          */
-        Cell &setPadding(int p)
-        { mPadding = p; return *this; }
+        LayoutCell &getCell()
+        { return *mCell; }
 
         /**
-         * Sets the horizontal alignment of the cell content.
+         * Returns a placer for the same container but to an inner cell.
          */
-        Cell &setHAlign(Alignment a)
-        { mAlign[0] = a; return *this; }
+        ContainerPlacer at(int x, int y);
 
         /**
-         * Sets the vertical alignment of the cell content.
+         * Adds the given widget to the container and places it in the layout.
+         * @see LayoutArray::place
          */
-        Cell &setVAlign(Alignment a)
-        { mAlign[1] = a; return *this; }
+        LayoutCell &operator()
+            (int x, int y, gcn::Widget *, int w = 1, int h = 1);
 
     private:
 
-        gcn::Widget *mWidget;
-        int mPadding;
-        int mExtent[2];
-        Alignment mAlign[2];
+        gcn::Container *mContainer;
+        LayoutCell *mCell;
 };
 
 /**
- * This class is an helper for setting the position of widgets. They are
- * positioned along the cells of a rectangular table.
- *
- * The size of a given table column can either be set manually or be chosen
- * from the widest widget of the column. An empty column has a FILL width,
- * which means it will be extended so that the layout fits its minimum width.
- *
- * The process is similar for table rows. By default, there is a spacing of 4
- * pixels between rows and between columns, and a margin of 6 pixels around the
- * whole layout.
+ * This class contains a rectangular array of cells.
  */
-class Layout
+class LayoutArray
 {
+    friend class LayoutCell;
+
     public:
 
-        Layout(): mSpacing(4), mMargin(6), mX(0), mY(0), mW(0), mH(0) {}
+        LayoutArray();
+
+        ~LayoutArray();
 
         /**
-         * Gets the x-coordinate of the top left point of the layout.
+         * Returns a reference on the cell at given position.
          */
-        int getX() const
-        { return mX; }
+        LayoutCell &at(int x, int y, int w = 1, int h = 1);
 
         /**
-         * Gets the y-coordinate of the top left point of the layout.
+         * Places a widget in a given cell.
+         * @param w number of columns the widget spawns.
+         * @param h number of rows the widget spawns.
+         * @note When @a w is 1, the width of column @a x is reset to zero if
+         *       it was FILL.
          */
-        int getY() const
-        { return mY; }
+        LayoutCell &place(gcn::Widget *, int x, int y, int w = 1, int h = 1);
 
         /**
          * Sets the minimum width of a column.
-         * @note Setting the width to FILL and then placing a widget in the
-         * column will reset the width to zero.
          */
         void setColWidth(int n, int w);
 
         /**
          * Sets the minimum height of a row.
-         * @note Setting the height to FILL and then placing a widget in the
-         * row will reset the height to zero.
          */
         void setRowHeight(int n, int h);
 
         /**
-         * Matchs widths of two columns.
+         * Sets the widths of two columns to the maximum of their widths.
          */
         void matchColWidth(int n1, int n2);
 
         /**
-         * Sets the minimum width of the layout.
+         * Computes and sets the positions of all the widgets.
+         * @param nW width of the array, used to resize the FILL columns.
+         * @param nH height of the array, used to resize the FILL rows.
          */
-        void setWidth(int w)
-        { mW = w; }
+        void reflow(int nX, int nY, int nW, int nH);
+
+    private:
+
+        // Copy not allowed, as the array owns all its cells.
+        LayoutArray(LayoutArray const &);
+        LayoutArray &operator=(LayoutArray const &);
 
         /**
-         * Sets the minimum height of the layout.
+         * Gets the position and size of a widget along a given axis
          */
-        void setHeight(int h)
-        { mH = h; }
+        void align(int &pos, int &size, int dim,
+                   LayoutCell const &cell, short *sizes) const;
 
         /**
-         * Sets the spacing between cells.
+         * Ensures the private vectors are large enough.
          */
-        void setSpacing(int p)
-        { mSpacing = p; }
+        void resizeGrid(int w, int h);
 
         /**
-         * Sets the margin around the layout.
+         * Gets the column/row sizes along a given axis.
+         * @param upp target size for the array. Ignored if FILL.
          */
-        void setMargin(int m)
-        { mMargin = m; }
+        std::vector< short > getSizes(int dim, int upp) const;
 
         /**
-         * Places a widget in a given cell.
+         * Gets the total size along a given axis.
          */
-        Cell &place(gcn::Widget *, int x, int y, int w, int h);
+        int getSize(int dim) const;
+
+        std::vector< short > mSizes[2];
+        std::vector< std::vector < LayoutCell * > > mCells;
+
+        char mSpacing;
+};
+
+/**
+ * This class describes the formatting of a widget in the cell of a layout
+ * table. Horizontally, a widget can either fill the width of the cell (minus
+ * the cell padding), or it can retain its size and be flushed left, or flush
+ * right, or centered in the cell. The process is similar for the vertical
+ * alignment, except that top is represented by LEFT and bottom by RIGHT.
+ */
+class LayoutCell
+{
+    friend class Layout;
+    friend class LayoutArray;
+
+    public:
+
+        enum Alignment
+        {
+            LEFT, RIGHT, CENTER, FILL
+        };
+
+        LayoutCell(): mType(NONE) {}
+
+        ~LayoutCell();
 
         /**
-         * Computes the positions of all the widgets. Returns the size of the
-         * layout.
+         * Sets the padding around the cell content.
          */
-        void reflow(int &nW, int &nH);
+        LayoutCell &setPadding(int p)
+        { mPadding = p; return *this; }
+
+        /**
+         * Sets the horizontal alignment of the cell content.
+         */
+        LayoutCell &setHAlign(Alignment a)
+        { mAlign[0] = a; return *this; }
+
+        /**
+         * Sets the vertical alignment of the cell content.
+         */
+        LayoutCell &setVAlign(Alignment a)
+        { mAlign[1] = a; return *this; }
+
+        /**
+         * @see LayoutArray::at
+         */
+        LayoutCell &at(int x, int y)
+        { return getArray().at(x, y); }
+
+        /**
+         * @see LayoutArray::place
+         */
+        LayoutCell &place(gcn::Widget *wg, int x, int y, int w = 1, int h = 1)
+        { return getArray().place(wg, x, y, w, h); }
 
         /**
-         * Reflows the current layout. Then starts a new layout just below with
-         * the same width.
+         * @see LayoutArray::matchColWidth
          */
-        void flush();
+        void matchColWidth(int n1, int n2)
+        { getArray().matchColWidth(n1, n2); }
+
+        /**
+         * @see LayoutArray::setColWidth
+         */
+        void setColWidth(int n, int w)
+        { getArray().setColWidth(n, w); }
+
+        /**
+         * @see LayoutArray::setRowHeight
+         */
+        void setRowHeight(int n, int h)
+        { getArray().setRowHeight(n, h); }
+
+        /**
+         * Sets the minimum widths and heights of this cell and of all the
+         * inner cells.
+         */
+        void computeSizes();
+
+    private:
+
+        // Copy not allowed, as the cell may own an array.
+        LayoutCell(LayoutCell const &);
+        LayoutCell &operator=(LayoutCell const &);
+
+        union
+        {
+            gcn::Widget *mWidget;
+            LayoutArray *mArray;
+        };
 
         enum
         {
-            FILL = -42, /**< Expand until the layout as the expected size. */
+            NONE, WIDGET, ARRAY
         };
 
-    private:
+        /**
+         * Returns the embedded array. Creates it if the cell does not contain
+         * anything yet. Aborts if it contains a widget.
+         */
+        LayoutArray &getArray();
 
         /**
-         * Gets the position and size of a widget along a given axis
+         * @see LayoutArray::reflow
          */
-        void align(int &pos, int &size, int dim,
-                   Cell const &cell, int *sizes) const;
+        void reflow(int nx, int ny, int nw, int nh);
+
+        short mSize[2];
+        char mPadding;
+        char mExtent[2];
+        char mAlign[2];
+        char mNbFill[2];
+        char mType;
+};
+
+/**
+ * This class is an helper for setting the position of widgets. They are
+ * positioned along the cells of some rectangular tables. The layout may either
+ * be a single table or a tree of nested tables.
+ *
+ * The size of a given table column can either be set manually or be chosen
+ * from the widest widget of the column. An empty column has a FILL width,
+ * which means it will be extended so that the layout fits its minimum width.
+ *
+ * The process is similar for table rows. By default, there is a spacing of 4
+ * pixels between rows and between columns, and a margin of 6 pixels around the
+ * whole layout.
+ */
+class Layout: public LayoutCell
+{
+    public:
+
+        Layout();
 
         /**
-         * Ensures the private vectors are large enough.
+         * Sets the margin around the layout.
          */
-        void resizeGrid(int w, int h);
+        void setMargin(int m)
+        { setPadding(m); }
 
         /**
-         * Gets the column/row sizes along a given axis.
+         * Sets the positions of all the widgets.
+         * @see LayoutArray::reflow
          */
-        std::vector< int > compute(int dim, int upp) const;
+        void reflow(int &nW, int &nH);
+
+        enum
+        {
+            FILL = -42, /**< Expand until the layout as the expected size. */
+        };
 
-        std::vector< int > mSizes[2];
-        std::vector< std::vector < Cell > > mCells;
+    private:
 
-        int mSpacing, mMargin;
-        int mX, mY, mW, mH, mNW, mNH;
+        bool mComputed;
 };
 
 #endif
diff --git a/src/gui/window.cpp b/src/gui/window.cpp
index 68b79367..7629e2e7 100644
--- a/src/gui/window.cpp
+++ b/src/gui/window.cpp
@@ -22,6 +22,7 @@
  */
 
 #include <algorithm>
+#include <cassert>
 #include <climits>
 
 #include <guichan/exception.hpp>
@@ -234,9 +235,8 @@ void Window::setSize(int width, int height)
 
     if (mLayout)
     {
-        mLayout->setWidth(width - 2 * getPadding());
-        mLayout->setHeight(height - getPadding() - getTitleBarHeight());
-        int w, h;
+        int w = width - 2 * getPadding(),
+            h = height - getPadding() - getTitleBarHeight();
         mLayout->reflow(w, h);
     }
 
@@ -520,7 +520,6 @@ void Window::mouseDragged(gcn::MouseEvent &event)
 
         // Set the new window and content dimensions
         setDimension(newDim);
-        updateContentSize();
     }
 }
 
@@ -555,7 +554,6 @@ void Window::resetToDefaultSize()
 {
     setPosition(mDefaultX, mDefaultY);
     setContentSize(mDefaultWidth, mDefaultHeight);
-    updateContentSize();
 }
 
 int Window::getResizeHandles(gcn::MouseEvent &event)
@@ -611,28 +609,22 @@ Layout &Window::getLayout()
     return *mLayout;
 }
 
-void Window::forgetLayout()
+LayoutCell &Window::place(int x, int y, gcn::Widget *wg, int w, int h)
 {
-    delete mLayout;
-    mLayout = 0;
+    add(wg);
+    return getLayout().place(wg, x, y, w, h);
 }
 
-Cell &Window::place(int x, int y, gcn::Widget *wg, int w, int h)
+ContainerPlacer Window::getPlacer(int x, int y)
 {
-    add(wg);
-    return getLayout().place(wg, x, y, w, h);
+    return ContainerPlacer(this, &getLayout().at(x, y));
 }
 
-void Window::reflowLayout()
+void Window::reflowLayout(int w, int h)
 {
-    if (!mLayout) return;
-    int w, h;
+    assert(mLayout);
     mLayout->reflow(w, h);
-    w += mLayout->getX();
-    h += mLayout->getY();
-    Layout *tmp = mLayout;
-    // Hide it so that the incoming resize does not reflow the layout again.
+    delete mLayout;
     mLayout = NULL;
     setContentSize(w, h);
-    mLayout = tmp;
 }
diff --git a/src/gui/window.h b/src/gui/window.h
index a09a9bbc..df756be3 100644
--- a/src/gui/window.h
+++ b/src/gui/window.h
@@ -30,11 +30,12 @@
 
 #include "windowlistener.h"
 
-class Cell;
 class ConfigListener;
+class ContainerPlacer;
 class Image;
 class ImageRect;
 class Layout;
+class LayoutCell;
 class ResizeGrip;
 class WindowContainer;
 
@@ -93,12 +94,6 @@ class Window : public gcn::Window
         void setContentSize(int width, int height);
 
         /**
-         * Called when either the user or resetToDefaultSize resizes the
-         * windows, so that the windows can manage its widgets.
-         */
-        virtual void updateContentSize() {}
-
-        /**
          * Sets the size of this window.
          */
         void setSize(int width, int height);
@@ -292,19 +287,24 @@ class Window : public gcn::Window
         Layout &getLayout();
 
         /**
-         * Deletes the layout handler.
+         * Computes the position of the widgets according to the current
+         * layout. Resizes the window so that the layout fits. Deletes the
+         * layout.
+         * @param w if non-zero, force the window to this width.
+         * @param h if non-zero, force the window to this height.
+         * @note This function is meant to be called with fixed-size windows.
          */
-        void forgetLayout();
+        void reflowLayout(int w = 0, int h = 0);
 
         /**
-         * Resizes the window after computing the position of the widgets.
+         * Adds a widget to the window and sets it at given cell.
          */
-        void reflowLayout();
+        LayoutCell &place(int x, int y, gcn::Widget *, int w = 1, int h = 1);
 
         /**
-         * Adds a widget to the window and sets it at given cell.
+         * Returns a proxy for adding widgets in an inner table of the layout.
          */
-        Cell &place(int x, int y, gcn::Widget *, int w = 1, int h = 1);
+        ContainerPlacer getPlacer(int x, int y);
 
     private:
         /**