/*

 * Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies). 

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Nokia Corporation - initial contribution.

 *

 * Contributors:

 *

 * Description:

 *

 * TraceViewer view key listener

 *

 */

package com.nokia.traceviewer.view.listener;

import org.eclipse.jface.text.TextViewer;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.KeyEvent;

import org.eclipse.swt.events.KeyListener;

import org.eclipse.swt.widgets.Slider;

import com.nokia.traceviewer.engine.StateHolder;

import com.nokia.traceviewer.engine.TraceViewerGlobals;

import com.nokia.traceviewer.engine.TraceViewerTraceViewInterface;

import com.nokia.traceviewer.engine.TraceViewerUtils;

import com.nokia.traceviewer.view.TraceViewerView;

/**

 * TraceViewer view key listener

 * 

 */

public class ViewerKeyListener implements KeyListener {

	/**

	 * The slider in the view

	 */

	private final Slider slider;

	/**

	 * The TextViewer in the view

	 */

	private final TextViewer viewer;

	/**

	 * TraceViewer view

	 */

	private final TraceViewerView view;

	/**

	 * Boolean determining if view should be updated after arrow up/down

	 */

	private boolean shouldBeUpdated;

	/**

	 * Font size

	 */

	private int fontSize = TraceViewerTraceViewInterface.FONT_SIZE;

	/**

	 * Max font size

	 */

	private static final int MAX_FONT_SIZE = 100;

	/**

	 * Constructor

	 * 

	 * @param slider

	 *            reference to the slider

	 * @param viewer

	 *            reference to the viewer

	 * @param view

	 *            reference to the view

	 */

	public ViewerKeyListener(Slider slider, TextViewer viewer,

			TraceViewerView view) {

		this.slider = slider;

		this.viewer = viewer;

		this.view = view;

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see

	 * org.eclipse.swt.events.KeyListener#keyPressed(org.eclipse.swt.events.

	 * KeyEvent)

	 */

	public void keyPressed(KeyEvent e) {

		int keyCode = e.keyCode;

		int showingTracesFrom = TraceViewerGlobals.getTraceViewer().getView()

				.getShowingTracesFrom();

		switch (keyCode) {

		// Page up pressed

		case SWT.PAGE_UP:

			// If there is at least one full page left in up of the cursor, we

			// just move the slider to where top index is

			if (viewer.getTopIndex() > (viewer.getBottomIndex() - viewer

					.getTopIndex())) {

				slider.setSelection(showingTracesFrom + viewer.getTopIndex());

				// If there is not at least one full page left, we move the

				// slider with one thumb

			} else {

				slider.setSelection(slider.getSelection() - slider.getThumb());

				TraceViewerGlobals.getTraceViewer().getStateHolder().setState(

						StateHolder.State.SCROLLING_WITH_PAGEUPDOWN);

			}

			break;

		// Page down pressed

		case SWT.PAGE_DOWN:

			// If there is at least full page left down from the cursor, we

			// just move the slider to where top index is

			if (viewer.getTopIndex() + viewer.getBottomIndex()

					- viewer.getTopIndex() + 2 < viewer.getTextWidget()

					.getLineCount()) {

				slider.setSelection(showingTracesFrom + viewer.getTopIndex());

				// If there is not full page left, we move the

				// slider with one thumb

			} else {

				slider.setSelection(slider.getSelection() + slider.getThumb());

				TraceViewerGlobals.getTraceViewer().getStateHolder().setState(

						StateHolder.State.SCROLLING_WITH_PAGEUPDOWN);

			}

			break;

		case SWT.ARROW_UP:

			// There is at least 1 row in top of the view, just move slider to

			// where top index is

			if (viewer.getTopIndex() > 0) {

				slider.setSelection(showingTracesFrom + viewer.getTopIndex());

			} else {

				// When we are in the first row, the second time is when we want

				// to update

				if (shouldBeUpdated) {

					TraceViewerGlobals.getTraceViewer().getStateHolder()

							.setState(StateHolder.State.SCROLLING_WITH_ARROWS);

					slider.setSelection(showingTracesFrom - 1);

					shouldBeUpdated = false;

				} else {

					shouldBeUpdated = true;

				}

			}

			removePossibleSelection(e.stateMask);

			break;

		case SWT.ARROW_DOWN:

			// There is at least 1 row in bottom of the view, just move slider

			// to where top index is

			if (viewer.getBottomIndex() < viewer.getTextWidget().getLineCount() - 1) {

				slider.setSelection(showingTracesFrom + viewer.getTopIndex());

			} else {

				TraceViewerGlobals.getTraceViewer().getStateHolder().setState(

						StateHolder.State.SCROLLING_WITH_ARROWS);

				slider.setSelection(slider.getSelection() + 1);

			}

			removePossibleSelection(e.stateMask);

			break;

		case SWT.ARROW_LEFT:

			// Fall through

		case SWT.ARROW_RIGHT:

			removePossibleSelection(e.stateMask);

			break;

		case SWT.HOME:

			// Ctrl was used

			if ((e.stateMask & SWT.CTRL) == SWT.CTRL) {

				// Shift was used

				if ((e.stateMask & SWT.SHIFT) == SWT.SHIFT) {

					SelectionProperties.lastClickedLine = 0;

					SelectionProperties.lastClickedLineCaretOffset = 0;

					SelectionProperties.lastClickedTimestamp = TraceViewerUtils

							.getTimestampStringForTrace(0);

				} else {

					SelectionProperties.firstClickedLine = 0;

					SelectionProperties.firstClickedLineCaretOffset = 0;

					SelectionProperties.firstClickedTimestamp = TraceViewerUtils

							.getTimestampStringForTrace(0);

					SelectionProperties.lastClickedLine = -1;

					SelectionProperties.lastClickedTimestamp = ""; //$NON-NLS-1$

				}

				// If we are in the first block

				if (isInFirstBlock()) {

					// Update trim and set selection

					ViewerSelectionChangedListener

							.handleTrimInformationUpdate();

					view.setSelection();

				}

				// Jump to first line

				viewer.getTextWidget().setCaretOffset(0);

				slider.setSelection(0);

				// Ctrl was not used

			} else {

				removePossibleSelection(e.stateMask);

			}

			break;

		case SWT.END:

			// Ctrl was used

			if ((e.stateMask & SWT.CTRL) == SWT.CTRL) {

				int traceCount = TraceViewerGlobals.getTraceViewer()

						.getDataReaderAccess().getCurrentDataReader()

						.getTraceCount();

				// Shift was used

				if ((e.stateMask & SWT.SHIFT) == SWT.SHIFT) {

					SelectionProperties.lastClickedLine = traceCount;

					SelectionProperties.lastClickedLineCaretOffset = 0;

					SelectionProperties.lastClickedTimestamp = TraceViewerUtils

							.getTimestampStringForTrace(traceCount - 1);

				} else {

					SelectionProperties.firstClickedLine = traceCount;

					SelectionProperties.firstClickedLineCaretOffset = 0;

					SelectionProperties.firstClickedTimestamp = TraceViewerUtils

							.getTimestampStringForTrace(traceCount - 1);

					SelectionProperties.lastClickedLine = -1;

					SelectionProperties.lastClickedTimestamp = ""; //$NON-NLS-1$

				}

				// If we are in the last block

				if (isInLastBlock()) {

					// Set the caret to the end

					viewer.getTextWidget().setCaretOffset(

							viewer.getTextWidget().getCharCount());

					viewer.setTopIndex(traceCount);

					// Update trim and set selection

					ViewerSelectionChangedListener

							.handleTrimInformationUpdate();

					view.setSelection();

					// Not in the last block

				} else {

					SelectionProperties.putCaretToTheEnd = true;

				}

				// Change the slider position

				slider.setSelection(traceCount);

				// Ctrl was not used

			} else {

				removePossibleSelection(e.stateMask);

			}

			break;

		// Search again

		case SWT.F3:

			String previousSearch = TraceViewerGlobals.getTraceViewer()

					.getDataProcessorAccess().getSearchProcessor()

					.getSearchDialog().getPreviousSearchString();

			if (!previousSearch.equals("")) { //$NON-NLS-1$

				TraceViewerGlobals.getTraceViewer().getDataProcessorAccess()

						.getSearchProcessor().searchTraceWithString(

								previousSearch);

			}

			break;

		default:

			break;

		}

		// Font size can be changed with CTRL + "+" or CTRL + "-" chars

		if (e.stateMask == SWT.CTRL) {

			switch (e.character) {

			case '+':

				if (fontSize++ <= MAX_FONT_SIZE) {

					TraceViewerGlobals.getTraceViewer().getView().setFontSize(

							fontSize);

				} else {

					fontSize = MAX_FONT_SIZE;

				}

				break;

			case '-':

				if (fontSize-- > 0) {

					TraceViewerGlobals.getTraceViewer().getView().setFontSize(

							fontSize);

				} else {

					fontSize = 1;

				}

				break;

			default:

				break;

			}

		}

		// Scroll to new line or get more data

		TraceViewerGlobals.getTraceViewer().getView().scrollViewToLine(

				slider.getSelection());

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see

	 * org.eclipse.swt.events.KeyListener#keyReleased(org.eclipse.swt.events

	 * .KeyEvent)

	 */

	public void keyReleased(KeyEvent e) {

	}

	/**

	 * Checks if we are in the last block of traces

	 * 

	 * @return true if we are in the last block of traces

	 */

	private boolean isInLastBlock() {

		boolean lastBlock = false;

		if (TraceViewerGlobals.getTraceViewer().getView()

				.getShowingTracesFrom()

				+ (2 * TraceViewerGlobals.blockSize) > TraceViewerGlobals

				.getTraceViewer().getDataReaderAccess().getCurrentDataReader()

				.getTraceCount()) {

			lastBlock = true;

		}

		return lastBlock;

	}

	/**

	 * Checks if we are in the first block of traces

	 * 

	 * @return true if we are in the first block of traces

	 */

	private boolean isInFirstBlock() {

		boolean firstBlock = false;

		if (TraceViewerGlobals.getTraceViewer().getView()

				.getShowingTracesFrom() == 0) {

			firstBlock = true;

		}

		return firstBlock;

	}

	/**

	 * Removes possible selection

	 * 

	 * @param stateMask

	 *            state mask for the key

	 */

	private void removePossibleSelection(int stateMask) {

		if (stateMask != SWT.SHIFT) {

			SelectionProperties.clear();

		}

	}

}