qgsmaptip.h

Go to the documentation of this file.

/***************************************************************************
    qgsmaptip.h  -  Query a layer and show a maptip on the canvas
    ---------------------
    begin                : October 2007
    copyright            : (C) 2007 by Gary Sherman
    email                : sherman @ mrcc dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
#ifndef QGSMAPTIP_H
#define QGSMAPTIP_H
 
class QgsMapLayer;
class QgsMapCanvas;
class QPoint;
class QString;
class QgsPointXY;
class QgsVectorLayer;
class QgsWebView;
 
#include "qgis_gui.h"
#include "qgsfeature.h"
 
#include <QTimer>
#include <QUrl>
#include <QWidget>

class GUI_EXPORT QgsMapTip : public QWidget
{
    Q_OBJECT
  public:
    QgsMapTip();

    void showMapTip( QgsMapLayer *thepLayer, QgsPointXY &mapPosition, const QPoint &pixelPosition, QgsMapCanvas *mpMapCanvas );

    void clear( QgsMapCanvas *mpMapCanvas = nullptr, int msDelay = 0 );

    static QString vectorMapTipPreviewText( QgsMapLayer *layer, QgsMapCanvas *mapCanvas, const QString &mapTemplate, const QString &displayExpression );

    static QString rasterMapTipPreviewText( QgsMapLayer *layer, QgsMapCanvas *mapCanvas, const QString &mapTemplate );
 
  private slots:
    void onLinkClicked( const QUrl &url );
    void resizeAndMoveToolTip();
 
  private:
    // Fetch the feature to use for the maptip text.
    // Only the first feature in the search radius is used
    QString fetchFeature( QgsMapLayer *thepLayer, QgsPointXY &mapPosition, QgsMapCanvas *mapCanvas );
 
    // Sample the raster and get the maptip text
    QString fetchRaster( QgsMapLayer *layer, QgsPointXY &mapPosition, QgsMapCanvas *mapCanvas );
 
    // Insert the raw map tip text into an HTML template and return the result
    static QString htmlText( const QString &text, int maxWidth = -1 );
 
    // Flag to indicate if a maptip is currently being displayed
    bool mMapTipVisible;
 
    QgsWebView *mWebView = nullptr;
 
    static const int MARGIN_VALUE = 5;
 
    QTimer mDelayedClearTimer;
 
    // Template for the actual HTML content that will be displayed in QgsWebView
    static const QString sMapTipTemplate;
 
    QPoint mPosition;
    const QgsMapCanvas *mMapCanvas = nullptr;
};
#endif // QGSMAPTIP_H