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	/*
	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package javax.swing.text;

	import java.awt.*;
	import javax.swing.*;
	import javax.swing.event.*;

	/**
	* Extends the multi-line plain text view to be suitable
	* for a single-line editor view. If the view is
	* allocated extra space, the field must adjust for it.
	* If the hosting component is a JTextField, this view
	* will manage the ranges of the associated BoundedRangeModel
	* and will adjust the horizontal allocation to match the
	* current visibility settings of the JTextField.
	*
	* @author Timothy Prinzing
	* @see View
	*/
	public class FieldView extends PlainView {

	/**
	* Constructs a new FieldView wrapped on an element.
	*
	* @param elem the element
	*/
	public FieldView(Element elem) {
	super(elem);
	}

	/**
	* Fetches the font metrics associated with the component hosting
	* this view.
	*
	* @return the metrics
	*/
	protected FontMetrics getFontMetrics() {
	Component c = getContainer();
	return c.getFontMetrics(c.getFont());
	}

	/**
	* Adjusts the allocation given to the view
	* to be a suitable allocation for a text field.
	* If the view has been allocated more than the
	* preferred span vertically, the allocation is
	* changed to be centered vertically. Horizontally
	* the view is adjusted according to the horizontal
	* alignment property set on the associated JTextField
	* (if that is the type of the hosting component).
	*
	* @param a the allocation given to the view, which may need
	* to be adjusted.
	* @return the allocation that the superclass should use.
	*/
	protected Shape adjustAllocation(Shape a) {
	if (a != null) {
	Rectangle bounds = a.getBounds();
	int vspan = (int) getPreferredSpan(Y_AXIS);
	int hspan = (int) getPreferredSpan(X_AXIS);
	if (bounds.height != vspan) {
	int slop = bounds.height - vspan;
	bounds.y += slop / 2;
	bounds.height -= slop;
	}

	// horizontal adjustments
	Component c = getContainer();
	if (c instanceof JTextField) {
	JTextField field = (JTextField) c;
	BoundedRangeModel vis = field.getHorizontalVisibility();
	int max = Math.max(hspan, bounds.width);
	int value = vis.getValue();
	int extent = Math.min(max, bounds.width - 1);
	if ((value + extent) > max) {
	value = max - extent;
	}
	vis.setRangeProperties(value, extent, vis.getMinimum(),
	max, false);
	if (hspan < bounds.width) {
	// horizontally align the interior
	int slop = bounds.width - 1 - hspan;

	int align = ((JTextField)c).getHorizontalAlignment();
	if(Utilities.isLeftToRight(c)) {
	if(align==LEADING) {
	align = LEFT;
	}
	else if(align==TRAILING) {
	align = RIGHT;
	}
	}
	else {
	if(align==LEADING) {
	align = RIGHT;
	}
	else if(align==TRAILING) {
	align = LEFT;
	}
	}

	switch (align) {
	case SwingConstants.CENTER:
	bounds.x += slop / 2;
	bounds.width -= slop;
	break;
	case SwingConstants.RIGHT:
	bounds.x += slop;
	bounds.width -= slop;
	break;
	}
	} else {
	// adjust the allocation to match the bounded range.
	bounds.width = hspan;
	bounds.x -= vis.getValue();
	}
	}
	return bounds;
	}
	return null;
	}

	/**
	* Update the visibility model with the associated JTextField
	* (if there is one) to reflect the current visibility as a
	* result of changes to the document model. The bounded
	* range properties are updated. If the view hasn't yet been
	* shown the extent will be zero and we just set it to be full
	* until determined otherwise.
	*/
	void updateVisibilityModel() {
	Component c = getContainer();
	if (c instanceof JTextField) {
	JTextField field = (JTextField) c;
	BoundedRangeModel vis = field.getHorizontalVisibility();
	int hspan = (int) getPreferredSpan(X_AXIS);
	int extent = vis.getExtent();
	int maximum = Math.max(hspan, extent);
	extent = (extent == 0) ? maximum : extent;
	int value = maximum - extent;
	int oldValue = vis.getValue();
	if ((oldValue + extent) > maximum) {
	oldValue = maximum - extent;
	}
	value = Math.max(0, Math.min(value, oldValue));
	vis.setRangeProperties(value, extent, 0, maximum, false);
	}
	}

	// --- View methods -------------------------------------------

	/**
	* Renders using the given rendering surface and area on that surface.
	* The view may need to do layout and create child views to enable
	* itself to render into the given allocation.
	*
	* @param g the rendering surface to use
	* @param a the allocated region to render into
	*
	* @see View#paint
	*/
	public void paint(Graphics g, Shape a) {
	Rectangle r = (Rectangle) a;
	g.clipRect(r.x, r.y, r.width, r.height);
	super.paint(g, a);
	}

	/**
	* Adjusts <code>a</code> based on the visible region and returns it.
	*/
	Shape adjustPaintRegion(Shape a) {
	return adjustAllocation(a);
	}

	/**
	* Determines the preferred span for this view along an
	* axis.
	*
	* @param axis may be either View.X_AXIS or View.Y_AXIS
	* @return the span the view would like to be rendered into >= 0.
	* Typically the view is told to render into the span
	* that is returned, although there is no guarantee.
	* The parent may choose to resize or break the view.
	*/
	public float getPreferredSpan(int axis) {
	switch (axis) {
	case View.X_AXIS:
	Segment buff = SegmentCache.getSharedSegment();
	Document doc = getDocument();
	int width;
	try {
	FontMetrics fm = getFontMetrics();
	doc.getText(0, doc.getLength(), buff);
	width = Utilities.getTabbedTextWidth(buff, fm, 0, this, 0);
	if (buff.count > 0) {
	Component c = getContainer();
	firstLineOffset = sun.swing.SwingUtilities2.
	getLeftSideBearing((c instanceof JComponent) ?
	(JComponent)c : null, fm,
	buff.array[buff.offset]);
	firstLineOffset = Math.max(0, -firstLineOffset);
	}
	else {
	firstLineOffset = 0;
	}
	} catch (BadLocationException bl) {
	width = 0;
	}
	SegmentCache.releaseSharedSegment(buff);
	return width + firstLineOffset;
	default:
	return super.getPreferredSpan(axis);
	}
	}

	/**
	* Determines the resizability of the view along the
	* given axis. A value of 0 or less is not resizable.
	*
	* @param axis View.X_AXIS or View.Y_AXIS
	* @return the weight -> 1 for View.X_AXIS, else 0
	*/
	public int getResizeWeight(int axis) {
	if (axis == View.X_AXIS) {
	return 1;
	}
	return 0;
	}

	/**
	* Provides a mapping from the document model coordinate space
	* to the coordinate space of the view mapped to it.
	*
	* @param pos the position to convert >= 0
	* @param a the allocated region to render into
	* @return the bounding box of the given position
	* @exception BadLocationException if the given position does not
	* represent a valid location in the associated document
	* @see View#modelToView
	*/
	public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
	return super.modelToView(pos, adjustAllocation(a), b);
	}

	/**
	* Provides a mapping from the view coordinate space to the logical
	* coordinate space of the model.
	*
	* @param fx the X coordinate >= 0.0f
	* @param fy the Y coordinate >= 0.0f
	* @param a the allocated region to render into
	* @return the location within the model that best represents the
	* given point in the view
	* @see View#viewToModel
	*/
	public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias) {
	return super.viewToModel(fx, fy, adjustAllocation(a), bias);
	}

	/**
	* Gives notification that something was inserted into the document
	* in a location that this view is responsible for.
	*
	* @param changes the change information from the associated document
	* @param a the current allocation of the view
	* @param f the factory to use to rebuild if the view has children
	* @see View#insertUpdate
	*/
	public void insertUpdate(DocumentEvent changes, Shape a, ViewFactory f) {
	super.insertUpdate(changes, adjustAllocation(a), f);
	updateVisibilityModel();
	}

	/**
	* Gives notification that something was removed from the document
	* in a location that this view is responsible for.
	*
	* @param changes the change information from the associated document
	* @param a the current allocation of the view
	* @param f the factory to use to rebuild if the view has children
	* @see View#removeUpdate
	*/
	public void removeUpdate(DocumentEvent changes, Shape a, ViewFactory f) {
	super.removeUpdate(changes, adjustAllocation(a), f);
	updateVisibilityModel();
	}

	}

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