grouplayout.java

j2me设计的界面包

     * <code>GroupLayout</code> is managing, it will be added to the
     * <code>Container</code>.
     *
     * @param component the component
     * @param honorsVisibility whether <code>component</code>'s visiblity should be
     *              considered for sizing and positioning
     * @throws IllegalArgumentException if <code>component</code> is <code>null</code>
     * @see #setHonorsVisibility(boolean)
     */
    public void setHonorsVisibility(Component component,
            Boolean honorsVisibility) {
        if (component == null) {
            throw new IllegalArgumentException("Component must be non-null");
        }
        getComponentInfo(component).setHonorsVisibility(honorsVisibility);
        springsChanged = true;
        isValid = false;
        invalidateHost();
    }

    /**
     * Returns a textual description of this GroupLayout.  The return value
     * is intended for debugging purposes only.
     *
     * @return textual description of this GroupLayout
     **/
    public String toString() {
        if (springsChanged) {
            registerComponents(horizontalGroup, HORIZONTAL);
            registerComponents(verticalGroup, VERTICAL);
        }
        StringBuffer buffer = new StringBuffer();
        buffer.append("HORIZONTAL\n");
        dump(buffer, horizontalGroup, "  ", HORIZONTAL);
        buffer.append("\nVERTICAL\n");
        dump(buffer, verticalGroup, "  ", VERTICAL);
        return buffer.toString();
    }
    
    private void dump(StringBuffer buffer, Spring spring, String indent,
            int axis) {
        String origin = "";
        String padding = "";
        if (spring instanceof ComponentSpring) {
            ComponentSpring cSpring = (ComponentSpring)spring;
            origin = Integer.toString(cSpring.getOrigin()) + " ";
            String name = cSpring.getComponent().toString();
            if (name != null) {
                origin = "name=" + name + ", ";
            }
        }
        if (spring instanceof AutopaddingSpring) {
            AutopaddingSpring paddingSpring = (AutopaddingSpring)spring;
            padding = ", userCreated=" + paddingSpring.getUserCreated() +
                    ", matches=" + paddingSpring.getMatchDescription();
        }
        buffer.append(indent + spring.getClass().getName() + " " +
                Integer.toHexString(spring.hashCode()) + " " +
                origin +
                ", size=" + spring.getSize() +
                ", alignment=" + spring.getAlignment() +
                " prefs=[" + spring.getMinimumSize(axis) +
                " " + spring.getPreferredSize(axis) +
                " " + spring.getMaximumSize(axis) + 
                padding + "]\n");
        if (spring instanceof Group) {
            Vector springs = ((Group)spring).springs;
            indent += "  ";
            for (int counter = 0; counter < springs.size(); counter++) {
                dump(buffer, (Spring)springs.elementAt(counter), indent, axis);
            }
        }
    }
    
    /**
     * Sets whether or not a gap between components 
     * should automatically be created.  For example, if this is true
     * and you add two components to a <code>SequentialGroup</code> a
     * gap between the two will automatically be created.  The default
     * is false.
     *
     * @param autocreatePadding whether or not to automatically created a gap
     *        between components and the container
     */
    public void setAutocreateGaps(boolean autocreatePadding) {
        if (this.autocreatePadding != autocreatePadding) {
            this.autocreatePadding = autocreatePadding;
            invalidateHost();
        }
    }
    
    /**
     * Returns true if gaps between components are automatically be created.
     *
     * @return true if gaps between components should automatically be created
     */
    public boolean getAutocreateGaps() {
        return autocreatePadding;
    }

    /**
     * Sets whether or not gaps between the container and the first/last
     * components should automatically be created. The default
     * is false.
     *
     * @param autocreatePadding whether or not to automatically create
     *        gaps between the container and first/last components.
     */
    public void setAutocreateContainerGaps(boolean autocreatePadding) {
        if (autocreatePadding != autocreateContainerPadding) {
            autocreateContainerPadding = autocreatePadding;
            horizontalGroup = createTopLevelGroup(getHorizontalGroup());
            verticalGroup = createTopLevelGroup(getVerticalGroup());
            invalidateHost();
        }
    }
    
    /**
     * Returns whether or not gaps between the container and the
     * first/last components should automatically be created. The default
     * is false.
     *
     * @return whether or not the gaps between the container and the
     *         first/last components should automatically be created
     */
    public boolean getAutocreateContainerGaps() {
        return autocreateContainerPadding;
    }

    /**
     * Sets the <code>Group</code> that is responsible for
     * layout along the horizontal axis.
     *
     * @param group <code>Group</code> responsible for layout along
     *          the horizontal axis
     * @throws IllegalArgumentException if group is null
     */
    public void setHorizontalGroup(Group group) {
        if (group == null) {
            throw new IllegalArgumentException("Group must be non-null");
        }
        horizontalGroup = createTopLevelGroup(group);
        invalidateHost();
    }
    
    /**
     * Returns the <code>Group</code> that is responsible for
     * layout along the horizontal axis.
     *
     * @return <code>ParallelGroup</code> responsible for layout along
     *          the horizontal axis.
     */
    public Group getHorizontalGroup() {
        int index = 0;
        if (horizontalGroup.springs.size() > 1) {
            index = 1;
        }
        return (Group)horizontalGroup.springs.elementAt(index);
    }
    
    /**
     * Sets the <code>Group</code> that is responsible for
     * layout along the vertical axis.
     *
     * @param group <code>Group</code> responsible for layout along
     *          the vertical axis.
     * @throws IllegalArgumentException if group is null.
     */
    public void setVerticalGroup(Group group) {
        if (group == null) {
            throw new IllegalArgumentException("Group must be non-null");
        }
        verticalGroup = createTopLevelGroup(group);
        invalidateHost();
    }
    
    /**
     * Returns the <code>ParallelGroup</code> that is responsible for
     * layout along the vertical axis.
     *
     * @return <code>ParallelGroup</code> responsible for layout along
     *          the vertical axis.
     */
    public Group getVerticalGroup() {
        int index = 0;
        if (verticalGroup.springs.size() > 1) {
            index = 1;
        }
        return (Group)verticalGroup.springs.elementAt(index);
    }

    /**
     * Wraps the user specified group in a sequential group.  If 
     * container gaps should be generate the necessary springs are
     * added.
     */
    private Group createTopLevelGroup(Group specifiedGroup) {
        SequentialGroup group = createSequentialGroup();
        if (getAutocreateContainerGaps()) {
            group.addSpring(new ContainerAutopaddingSpring());
            group.add(specifiedGroup);
            group.addSpring(new ContainerAutopaddingSpring());
        } else {
            group.add(specifiedGroup);
        }
        return group;
    }

    /**
     * Creates and returns a <code>SequentialGroup</code>.
     *
     * @return a new <code>SequentialGroup</code>
     */
    public SequentialGroup createSequentialGroup() {
        return new SequentialGroup();
    }
    
    /**
     * Creates and returns a <code>ParallelGroup</code> with a
     * <code>LEADING</code> alignment.  This is a cover method for the more
     * general <code>createParallelGroup(int)</code> method.
     *
     * @return a new ParallelGroup
     * @see #createParallelGroup(int)
     */
    public ParallelGroup createParallelGroup() {
        return createParallelGroup(LEADING);
    }
    
    /**
     * Creates and returns an <code>ParallelGroup</code>.  The alignment
     * specifies how children elements should be positioned when the
     * the parallel group is given more space than necessary.  For example,
     * if a ParallelGroup with an alignment of TRAILING is given 100 pixels
     * and a child only needs 50 pixels, the child will be positioned at the
     * position 50.
     *
     * @param alignment alignment for the elements of the Group, one
     *        of <code>LEADING</code>, <code>TRAILING</code>,
     *        <code>CENTER</code> or <code>BASELINE</code>.
     * @throws IllegalArgumentException if alignment is not one of
     *         <code>LEADING</code>, <code>TRAILING</code>,
     *         <code>CENTER</code> or <code>BASELINE</code>
     * @return a new <code>ParallelGroup</code>
     */
    public ParallelGroup createParallelGroup(int alignment) {
        return createParallelGroup(alignment, true);
    }
    
    /**
     * Creates and returns an <code>ParallelGroup</code>.  The alignment
     * specifies how children elements should be positioned when the
     * the parallel group is given more space than necessary.  For example,
     * if a ParallelGroup with an alignment of TRAILING is given 100 pixels
     * and a child only needs 50 pixels, the child will be positioned at the
     * position 50.
     *
     * @param alignment alignment for the elements of the Group, one
     *        of <code>LEADING</code>, <code>TRAILING</code>,
     *        <code>CENTER</code> or <code>BASELINE</code>.
     * @param resizable whether or not the group is resizable.  If the group
     *        is not resizable the min/max size will be the same as the
     *        preferred.
     * @throws IllegalArgumentException if alignment is not one of
     *         <code>LEADING</code>, <code>TRAILING</code>,
     *         <code>CENTER</code> or <code>BASELINE</code>
     * @return a new <code>ParallelGroup</code>
     */
    public ParallelGroup createParallelGroup(int alignment, boolean resizable) {
        if (alignment == BASELINE) {
            return new BaselineGroup(resizable);
        }
        return new ParallelGroup(alignment, resizable);
    }
    
    /**
     * Creates and returns a <code>ParallelGroup</code> that aligns it's
     * elements along the baseline. 
     *
     * @param resizable whether the group is resizable
     * @param anchorBaselineToTop whether the baseline is anchored to
     *        the top or bottom of the group
     * @see #createBaselineGroup
     * @see ParallelGroup
     */
    public ParallelGroup createBaselineGroup(boolean resizable,
            boolean anchorBaselineToTop) {
        return new BaselineGroup(resizable, anchorBaselineToTop);
    }
    
    /**
     * Forces the set of components to have the same size.
     * This can be used multiple times to force
     * any number of components to share the same size.
     * <p>
     * Linked Components are not be resizable.
     *
     * @param components Components to force to have same size.
     * @throws IllegalArgumentException if <code>components</code> is
     *         null, or contains null.
     */
    public void linkSize(Component[] components) {
        linkSize(components, HORIZONTAL | VERTICAL);
    }
    
    /**
     * Forces the set of components to have the same size.
     * This can be used multiple times to force
     * any number of components to share the same size.
     * <p>
     * Linked Components are not be resizable.
     *
     * @param components Components to force to have same size.
     * @param axis Axis to bind size, one of HORIZONTAL, VERTICAL or
     *             HORIZONTAL | VERTICAL
     * @throws IllegalArgumentException if <code>components</code> is
     *         null, or contains null.
     * @throws IllegalArgumentException if <code>axis</code> does not
     *         contain <code>HORIZONTAL</code> or <code>VERTICAL</code>
     */
    public void linkSize(Component[] components, int axis) {
        if (components == null) {
            throw new IllegalArgumentException("Components must be non-null");
        }
        boolean horizontal = ((axis & HORIZONTAL) == HORIZONTAL);
        boolean vertical = ((axis & VERTICAL) == VERTICAL);
        if (!vertical && !horizontal) {
            throw new IllegalArgumentException(
                    "Axis must contain HORIZONTAL or VERTICAL");
        }
        for (int counter = components.length - 1; counter >= 0; counter--) {
            Component c = components[counter];
            if (components[counter] == null) {
                throw new IllegalArgumentException(
                        "Components must be non-null");
            }
            // Force the component to be added
            getComponentInfo(c);
        }
        if (horizontal) {
            linkSize0(components, HORIZONTAL);
        }
        if (vertical) {