/*
* This library is part of Geranium -
* an open source UI library for GWT.
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)-
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* For further information about Alkacon Software, please see the
* company website: http://www.alkacon.com
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.alkacon.geranium.client.ui;
import com.alkacon.geranium.client.ui.css.I_LayoutBundle;
import com.alkacon.geranium.client.util.PositionBean;
import com.alkacon.geranium.client.util.PositionBean.Area;
import java.util.Iterator;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.dom.client.Style;
import com.google.gwt.dom.client.Style.Cursor;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.HasClickHandlers;
import com.google.gwt.event.dom.client.HasMouseDownHandlers;
import com.google.gwt.event.dom.client.HasMouseMoveHandlers;
import com.google.gwt.event.dom.client.HasMouseUpHandlers;
import com.google.gwt.event.dom.client.MouseDownEvent;
import com.google.gwt.event.dom.client.MouseDownHandler;
import com.google.gwt.event.dom.client.MouseMoveEvent;
import com.google.gwt.event.dom.client.MouseMoveHandler;
import com.google.gwt.event.dom.client.MouseUpEvent;
import com.google.gwt.event.dom.client.MouseUpHandler;
import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTMLPanel;
import com.google.gwt.user.client.ui.HasWidgets;
import com.google.gwt.user.client.ui.IndexedPanel;
import com.google.gwt.user.client.ui.Widget;
/**
* Select area widget. Allows the user to select an area inside the widget.<p>
*/
public class AreaSelectPanel extends Composite
implements HasWidgets, IndexedPanel, HasValueChangeHandlers<PositionBean>, HasMouseDownHandlers, HasMouseUpHandlers,
HasClickHandlers, HasMouseMoveHandlers, MouseDownHandler, MouseUpHandler, MouseMoveHandler {
/** The ui-binder interface. */
protected interface I_AreaSelectPanelUiBinder extends UiBinder<HTMLPanel, AreaSelectPanel> {
// GWT interface, nothing to do
}
/** States of the slect area panel. */
private enum State {
/** Dragging the selection. */
DRAGGING,
/** Nothing selected. */
EMPTY,
/** Resizing the height. */
RESIZE_HEIGHT,
/** Resizing the width. */
RESIZE_WIDTH,
/** Selected. */
SELECTED,
/** Selecting new selection. */
SELECTING
}
/** The ui-binder for this widget. */
private static I_AreaSelectPanelUiBinder m_uiBinder = GWT.create(I_AreaSelectPanelUiBinder.class);
/** The marker. */
@UiField
protected Element m_marker;
/** Select overlay. */
@UiField
protected Element m_overlayBottom;
/** Select overlay. */
@UiField
protected Element m_overlayLeft;
/** Select overlay. */
@UiField
protected Element m_overlayRight;
/** Select overlay. */
@UiField
protected Element m_overlayTop;
/** The panel holding added widgets. */
@UiField
protected FlowPanel m_panel;
/** The currently selected area. */
private PositionBean m_currentSelection;
/** Select area size. */
private int m_elementHeight;
/** Select area size. */
private int m_elementWidth;
/** Starting point of the selection. */
private int m_firstX;
/** Starting point of the selection. */
private int m_firstY;
/** Fixed selection ratio. */
private double m_heightToWidth;
/** Fire all events flag. */
private boolean m_isFireAll;
/** The main widget. */
private HTMLPanel m_main;
/** Style of the selection marker. */
private Style m_markerStyle;
/** Mouse over area. */
private Area m_mouseOverArea;
/** Cursor offset while dragging a selection. */
private int m_moveOffsetX;
/** Cursor offset while dragging a selection. */
private int m_moveOffsetY;
/** Style of image overlay. */
private Style m_overlayBottomStyle;
/** Style of image overlay. */
private Style m_overlayLeftStyle;
/** Style of image overlay. */
private Style m_overlayRightStyle;
/** Style of image overlay. */
private Style m_overlayTopStyle;
/** Select area state. */
private State m_state;
/**
* Constructor.<p>
*/
public AreaSelectPanel() {
m_main = m_uiBinder.createAndBindUi(this);
initWidget(m_main);
m_state = State.EMPTY;
m_heightToWidth = 0;
setHandlers();
m_markerStyle = m_marker.getStyle();
m_overlayLeftStyle = m_overlayLeft.getStyle();
m_overlayBottomStyle = m_overlayBottom.getStyle();
m_overlayRightStyle = m_overlayRight.getStyle();
m_overlayTopStyle = m_overlayTop.getStyle();
}
/**
* @see com.google.gwt.user.client.ui.HasWidgets#add(com.google.gwt.user.client.ui.Widget)
*/
public void add(Widget w) {
m_panel.add(w);
}
/**
* @see com.google.gwt.event.dom.client.HasClickHandlers#addClickHandler(com.google.gwt.event.dom.client.ClickHandler)
*/
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addDomHandler(handler, ClickEvent.getType());
}
/**
* @see com.google.gwt.event.dom.client.HasMouseDownHandlers#addMouseDownHandler(com.google.gwt.event.dom.client.MouseDownHandler)
*/
public HandlerRegistration addMouseDownHandler(MouseDownHandler handler) {
return addDomHandler(handler, MouseDownEvent.getType());
}
/**
* @see com.google.gwt.event.dom.client.HasMouseMoveHandlers#addMouseMoveHandler(com.google.gwt.event.dom.client.MouseMoveHandler)
*/
public HandlerRegistration addMouseMoveHandler(MouseMoveHandler handler) {
return addDomHandler(handler, MouseMoveEvent.getType());
}
/**
* @see com.google.gwt.event.dom.client.HasMouseUpHandlers#addMouseUpHandler(com.google.gwt.event.dom.client.MouseUpHandler)
*/
public HandlerRegistration addMouseUpHandler(MouseUpHandler handler) {
return addDomHandler(handler, MouseUpEvent.getType());
}
/**
* @see com.google.gwt.event.logical.shared.HasValueChangeHandlers#addValueChangeHandler(com.google.gwt.event.logical.shared.ValueChangeHandler)
*/
public HandlerRegistration addValueChangeHandler(ValueChangeHandler<PositionBean> handler) {
return addHandler(handler, ValueChangeEvent.getType());
}
/**
* @see com.google.gwt.user.client.ui.HasWidgets#clear()
*/
public void clear() {
m_panel.clear();
}
/**
* Removes the current selection.<p>
*/
public void clearSelection() {
m_state = State.EMPTY;
showSelect(false);
m_currentSelection = null;
}
/**
* Returns the position of the selected area, or <code>null</code> if nothing is selected.<p>
*
* @param relative if <code>true</code> the relative position is returned, otherwise the absolute position
*
* @return the position of the selected area
*/
public PositionBean getAreaPosition(boolean relative) {
// returning the relative position
if (relative) {
return new PositionBean(m_currentSelection);
}
// returning the absolute position
PositionBean abs = new PositionBean(m_currentSelection);
abs.setTop(m_currentSelection.getTop() + getElement().getAbsoluteTop());
abs.setLeft(m_currentSelection.getLeft() + getElement().getAbsoluteLeft());
return abs;
}
/**
* Sets the selection area.<p>
*
* @param relative <code>true</code> if provided position is relative to the select area, not absolute to the page
* @param pos the area position to select
*/
public void setAreaPosition(boolean relative, PositionBean pos) {
if (pos == null) {
return;
}
m_state = State.SELECTED;
showSelect(true);
m_currentSelection = new PositionBean();
m_firstX = pos.getLeft();
m_firstY = pos.getTop();
if (!relative) {
m_firstX -= getElement().getAbsoluteLeft();
m_firstY -= getElement().getAbsoluteTop();
}
// setSelectPosition(m_firstX, m_firstY, 0, 0);
setSelectPosition(m_firstX, m_firstY, pos.getHeight(), pos.getWidth());
}
/**
* @see com.google.gwt.user.client.ui.IndexedPanel#getWidget(int)
*/
public Widget getWidget(int index) {
return m_panel.getWidget(index);
}
/**
* @see com.google.gwt.user.client.ui.IndexedPanel#getWidgetCount()
*/
public int getWidgetCount() {
return m_panel.getWidgetCount();
}
/**
* @see com.google.gwt.user.client.ui.IndexedPanel#getWidgetIndex(com.google.gwt.user.client.ui.Widget)
*/
public int getWidgetIndex(Widget child) {
return m_panel.getWidgetIndex(child);
}
/**
* Returns if the value change event will always be fired, or only when a select/resize/move operation is finished.<p>
*
* @return <code>true</code> if the value change event will always be fired
*/
public boolean isFireAll() {
return m_isFireAll;
}
/**
* @see com.google.gwt.user.client.ui.HasWidgets#iterator()
*/
public Iterator<Widget> iterator() {
return m_panel.iterator();
}
/**
* @see com.google.gwt.event.dom.client.MouseDownHandler#onMouseDown(com.google.gwt.event.dom.client.MouseDownEvent)
*/
public void onMouseDown(MouseDownEvent event) {
if (event.getNativeButton() != NativeEvent.BUTTON_LEFT) {
// only act on left button down, ignore right click
return;
}
cacheElementSize();
switch (m_state) {
case EMPTY:
DOM.setCapture(getElement());
m_state = State.SELECTING;
m_firstX = event.getRelativeX(getElement());
m_firstY = event.getRelativeY(getElement());
m_currentSelection = new PositionBean();
setSelectPosition(m_firstX, m_firstY, 0, 0);
showSelect(true);
break;
case SELECTED:
m_firstX = event.getRelativeX(getElement());
m_firstY = event.getRelativeY(getElement());
if (m_mouseOverArea == null) {
// mouse not over selection, remove selection
clearSelection();
fireChangeEvent(true);
break;
}
switch (m_mouseOverArea) {
case BORDER_TOP:
m_state = State.RESIZE_HEIGHT;
// fixing opposite border
m_firstX = m_currentSelection.getLeft();
m_firstY = m_currentSelection.getTop() + m_currentSelection.getHeight();
break;
case BORDER_BOTTOM:
m_state = State.RESIZE_HEIGHT;
// fixing opposite border
m_firstX = m_currentSelection.getLeft();
m_firstY = m_currentSelection.getTop();
break;
case BORDER_LEFT:
m_state = State.RESIZE_WIDTH;
// fixing opposite border
m_firstX = m_currentSelection.getLeft() + m_currentSelection.getWidth();
m_firstY = m_currentSelection.getTop();
break;
case BORDER_RIGHT:
m_state = State.RESIZE_WIDTH;
// fixing opposite border
m_firstX = m_currentSelection.getLeft();
m_firstY = m_currentSelection.getTop();
break;
case CENTER:
m_state = State.DRAGGING;
m_moveOffsetX = m_firstX - m_currentSelection.getLeft();
m_moveOffsetY = m_firstY - m_currentSelection.getTop();
break;
case CORNER_BOTTOM_LEFT:
m_state = State.SELECTING;
// fixing opposite corner
m_firstX = m_currentSelection.getLeft() + m_currentSelection.getWidth();
m_firstY = m_currentSelection.getTop();
break;
case CORNER_BOTTOM_RIGHT:
m_state = State.SELECTING;
// fixing opposite corner
m_firstX = m_currentSelection.getLeft();
m_firstY = m_currentSelection.getTop();
break;
case CORNER_TOP_LEFT:
m_state = State.SELECTING;
// fixing opposite corner
m_firstX = m_currentSelection.getLeft() + m_currentSelection.getWidth();
m_firstY = m_currentSelection.getTop() + m_currentSelection.getHeight();
break;
case CORNER_TOP_RIGHT:
m_state = State.SELECTING;
// fixing opposite corner
m_firstX = m_currentSelection.getLeft();
m_firstY = m_currentSelection.getTop() + m_currentSelection.getHeight();
break;
default:
}
DOM.setCapture(getElement());
break;
case DRAGGING:
case RESIZE_HEIGHT:
case RESIZE_WIDTH:
case SELECTING:
default:
// Messed up selection state.
// May happen if mouse-cursor was moved outside the window or frame while button pressed and button was released outside.
if (m_currentSelection != null) {
m_state = State.SELECTED;
fireChangeEvent(true);
} else {
// this should never happen
clearSelection();
}
}
event.preventDefault();
event.stopPropagation();
}
/**
* @see com.google.gwt.event.dom.client.MouseMoveHandler#onMouseMove(com.google.gwt.event.dom.client.MouseMoveEvent)
*/
public void onMouseMove(MouseMoveEvent event) {
int secondX = event.getRelativeX(getElement());
int secondY = event.getRelativeY(getElement());
cacheElementSize();
// restricting cursor input to the area of the select panel
secondX = (secondX < 0) ? 0 : ((secondX > m_elementWidth) ? m_elementWidth : secondX);
secondY = (secondY < 0) ? 0 : ((secondY > m_elementHeight) ? m_elementHeight : secondY);
switch (m_state) {
case SELECTING:
if (m_heightToWidth > 0) {
// fixed height to width ratio
// calculate the appropriate dimensions
int tempX = getXForY(secondX, secondY);
if (((tempX > secondX) && (secondX > m_firstX)) || ((tempX < secondX) && (secondX < m_firstX))) {
secondY = getYForX(secondX, secondY);
} else {
secondX = tempX;
}
}
positionX(secondX);
positionY(secondY);
fireChangeEvent(false);
break;
case DRAGGING:
moveTo(secondX - m_moveOffsetX, secondY - m_moveOffsetY);
fireChangeEvent(false);
break;
case RESIZE_HEIGHT:
if (m_heightToWidth > 0) {
// fixed ratio, need the recalculate width to
int tempX = getXForY(secondX, secondY);
if ((tempX < 0) || (tempX > m_elementWidth)) {
tempX = secondX;
secondY = getYForX(secondX, secondY);
}
positionX(tempX);
}
positionY(secondY);
fireChangeEvent(false);
break;
case RESIZE_WIDTH:
if (m_heightToWidth > 0) {
// fixed ratio, need the recalculate height to
int tempY = getYForX(secondX, secondY);
if ((tempY < 0) || (tempY > m_elementWidth)) {
tempY = secondY;
secondX = getXForY(secondX, secondY);
}
positionY(getYForX(secondX, secondY));
}
positionX(secondX);
fireChangeEvent(false);
break;
case SELECTED:
// read over which area of the selection the cursor is positioned
m_mouseOverArea = m_currentSelection.getArea(secondX, secondY, 30);
// show the appropriate cursor
if (m_mouseOverArea == null) {
m_markerStyle.setCursor(Cursor.DEFAULT);
break;
}
switch (m_mouseOverArea) {
case BORDER_LEFT:
case BORDER_RIGHT:
m_markerStyle.setCursor(Cursor.E_RESIZE);
break;
case BORDER_TOP:
case BORDER_BOTTOM:
m_markerStyle.setCursor(Cursor.N_RESIZE);
break;
case CENTER:
m_markerStyle.setCursor(Cursor.MOVE);
break;
case CORNER_BOTTOM_RIGHT:
case CORNER_TOP_LEFT:
m_markerStyle.setCursor(Cursor.NW_RESIZE);
break;
case CORNER_TOP_RIGHT:
case CORNER_BOTTOM_LEFT:
m_markerStyle.setCursor(Cursor.NE_RESIZE);
break;
default:
}
break;
case EMPTY:
default:
}
}
/**
* @see com.google.gwt.event.dom.client.MouseUpHandler#onMouseUp(com.google.gwt.event.dom.client.MouseUpEvent)
*/
public void onMouseUp(MouseUpEvent event) {
switch (m_state) {
case SELECTING:
case DRAGGING:
case RESIZE_HEIGHT:
case RESIZE_WIDTH:
m_state = State.SELECTED;
m_mouseOverArea = null;
fireChangeEvent(true);
DOM.releaseCapture(getElement());
event.preventDefault();
event.stopPropagation();
break;
case SELECTED:
case EMPTY:
default:
}
}
/**
* @see com.google.gwt.user.client.ui.IndexedPanel#remove(int)
*/
public boolean remove(int index) {
return m_panel.remove(index);
}
/**
* @see com.google.gwt.user.client.ui.HasWidgets#remove(com.google.gwt.user.client.ui.Widget)
*/
public boolean remove(Widget w) {
return m_panel.remove(w);
}
/**
* Sets if the value change event will always be fired, or only when a select/resize/move operation is finished.<p>
*
* @param isFireAll <code>true</code> to always be fire the value change event
*/
public void setFireAll(boolean isFireAll) {
m_isFireAll = isFireAll;
}
/**
* Sets a fixed selection ratio. Set <code>0</code> to remove the fix.<p>
*
* @param heightToWidth the height to width ratio
*/
public void setRatio(double heightToWidth) {
m_heightToWidth = heightToWidth;
}
/**
* Caches the select area element size.<p>
*/
private void cacheElementSize() {
// cache element size if necessary
if ((m_elementHeight == 0) && (m_elementWidth == 0)) {
m_elementHeight = getElement().getOffsetHeight();
m_elementWidth = getElement().getOffsetWidth();
}
}
/**
* Fires the value change event.<p>
*
* @param alwaysFire <code>true</code> to always fire the change event, ignoring the fire all flag
*/
private void fireChangeEvent(boolean alwaysFire) {
if (alwaysFire || m_isFireAll) {
ValueChangeEvent.fire(this, m_currentSelection);
}
}
/**
* Calculates the matching X (left/width) value in case of a fixed height/width ratio.<p>
*
* @param newX the cursor X offset to the selection area
* @param newY the cursor Y offset to the selection area
*
* @return the matching X value
*/
private int getXForY(int newX, int newY) {
int width = (int)Math.floor((newY - m_firstY) / m_heightToWidth);
int result = m_firstX + width;
if (((m_firstX - newX) * (m_firstX - result)) < 0) {
result = m_firstX - width;
}
return result;
}
/**
* Calculates the matching Y (top/height) value in case of a fixed height/width ratio.<p>
*
* @param newX the cursor X offset to the selection area
* @param newY the cursor Y offset to the selection area
*
* @return the matching Y value
*/
private int getYForX(int newX, int newY) {
int height = (int)Math.floor((newX - m_firstX) * m_heightToWidth);
int result = m_firstY + height;
if (((m_firstY - newY) * (m_firstY - result)) < 0) {
result = m_firstY - height;
}
return result;
}
/**
* Moves the select area to the specified position, while keeping the size.<p>
*
* @param posX the new X position
* @param posY the new Y position
*/
private void moveTo(int posX, int posY) {
posX = (posX < 0) ? 0 : (((posX + m_currentSelection.getWidth()) >= m_elementWidth) ? m_elementWidth
- m_currentSelection.getWidth() : posX);
posY = (posY < 0) ? 0 : (((posY + m_currentSelection.getHeight()) >= m_elementHeight) ? m_elementHeight
- m_currentSelection.getHeight() : posY);
m_markerStyle.setTop(posY, Unit.PX);
m_markerStyle.setLeft(posX, Unit.PX);
m_overlayLeftStyle.setWidth(posX, Unit.PX);
m_overlayTopStyle.setLeft(posX, Unit.PX);
m_overlayTopStyle.setHeight(posY, Unit.PX);
m_overlayBottomStyle.setLeft(posX, Unit.PX);
m_overlayBottomStyle.setHeight(m_elementHeight - posY - m_currentSelection.getHeight(), Unit.PX);
m_overlayRightStyle.setWidth(m_elementWidth - posX - m_currentSelection.getWidth(), Unit.PX);
m_currentSelection.setTop(posY);
m_currentSelection.setLeft(posX);
}
/**
* Setting a new left/top value for the selection.<p>
*
* @param secondX the cursor X offset to the selection area
*/
private void positionX(int secondX) {
if (secondX < m_firstX) {
setSelectPositionX(secondX, m_firstX - secondX);
} else {
setSelectWidth(secondX - m_firstX);
}
}
/**
* Setting a new top/height value for the selection.<p>
*
* @param secondY the cursor Y offset to the selection area
*/
private void positionY(int secondY) {
if (secondY < m_firstY) {
setSelectPositionY(secondY, m_firstY - secondY);
} else {
setSelectHeight(secondY - m_firstY);
}
}
/**
* Sets self as mouse down, up and move handler.<p>
*/
private void setHandlers() {
addMouseDownHandler(this);
addMouseMoveHandler(this);
addMouseUpHandler(this);
}
/**
* Adjusts the select area height, while keeping the Y position of the top/left corner.<p>
*
* @param height the new height
*/
private void setSelectHeight(int height) {
m_markerStyle.setHeight(height, Unit.PX);
m_overlayBottomStyle.setHeight(m_elementHeight - m_currentSelection.getTop() - height, Unit.PX);
m_currentSelection.setHeight(height);
}
/**
* Sets position and size of the select area.<p>
*
* @param posX the new X position
* @param posY the new Y position
* @param height the new height
* @param width the new width
*/
private void setSelectPosition(int posX, int posY, int height, int width) {
setSelectPositionX(posX, width);
setSelectPositionY(posY, height);
}
/**
* Sets X position and width of the select area.<p>
*
* @param posX the new X position
* @param width the new width
*/
private void setSelectPositionX(int posX, int width) {
m_markerStyle.setLeft(posX, Unit.PX);
m_markerStyle.setWidth(width, Unit.PX);
m_overlayLeftStyle.setWidth(posX, Unit.PX);
m_overlayTopStyle.setLeft(posX, Unit.PX);
m_overlayTopStyle.setWidth(width, Unit.PX);
m_overlayBottomStyle.setLeft(posX, Unit.PX);
m_overlayBottomStyle.setWidth(width, Unit.PX);
m_overlayRightStyle.setWidth(m_elementWidth - posX - width, Unit.PX);
m_currentSelection.setLeft(posX);
m_currentSelection.setWidth(width);
}
/**
* Sets Y position and height of the select area.<p>
*
* @param posY the new Y position
* @param height the new height
*/
private void setSelectPositionY(int posY, int height) {
m_markerStyle.setTop(posY, Unit.PX);
m_markerStyle.setHeight(height, Unit.PX);
m_overlayTopStyle.setHeight(posY, Unit.PX);
m_overlayBottomStyle.setHeight(m_elementHeight - posY - height, Unit.PX);
m_currentSelection.setTop(posY);
m_currentSelection.setHeight(height);
}
/**
* Adjusts the select area width, while keeping the X position of the top/left corner.<p>
*
* @param width the new width
*/
private void setSelectWidth(int width) {
m_markerStyle.setWidth(width, Unit.PX);
m_overlayTopStyle.setWidth(width, Unit.PX);
m_overlayBottomStyle.setWidth(width, Unit.PX);
m_overlayRightStyle.setWidth(m_elementWidth - m_currentSelection.getLeft() - width, Unit.PX);
m_currentSelection.setWidth(width);
}
/**
* Shows or hides the select area.<p>
*
* @param show if <code>true</code> the select area will be shown
*/
private void showSelect(boolean show) {
if (show) {
m_main.addStyleName(I_LayoutBundle.INSTANCE.selectAreaCss().showSelect());
return;
}
m_main.removeStyleName(I_LayoutBundle.INSTANCE.selectAreaCss().showSelect());
}
}