From 982a88b5e2ad2c03570e878b23e4ed149483cb2c Mon Sep 17 00:00:00 2001
From: mgrojo <mgrojo@gmail.com>
Date: Thu, 14 Dec 2017 23:38:33 +0100
Subject: [PATCH] Avoid crash performing the correct check to know if the plot
 has graphs

This crash was introduced in 6d3228a0e3b7b5149dbe7207813196bbb04e85c6. It
happened when no previous settings were saved for the plot.

Additionally the plot interaction are set once for the plot widget.

This was reported at issue #838.
---
 src/PlotDock.cpp | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/src/PlotDock.cpp b/src/PlotDock.cpp
index 586af308..f7b3ba88 100644
--- a/src/PlotDock.cpp
+++ b/src/PlotDock.cpp
@@ -29,6 +29,12 @@ PlotDock::PlotDock(QWidget* parent)
     connect(ui->plotWidget, SIGNAL(mousePress(QMouseEvent*)), this, SLOT(mousePress()));
     connect(ui->plotWidget, SIGNAL(mouseWheel(QWheelEvent*)), this, SLOT(mouseWheel()));
 
+    // Enable: click on items to select them, Ctrl+Click for multi-selection, mouse-wheel for zooming and mouse drag for
+    // changing the visible range.
+    // Select one axis for zoom and drag applying only to that orientation.
+    ui->plotWidget->setInteractions(QCP::iSelectPlottables | QCP::iMultiSelect | QCP::iRangeZoom | QCP::iRangeDrag | QCP::iSelectAxes);
+    ui->plotWidget->setSelectionRectMode(QCP::srmNone);
+
     QShortcut* shortcutCopy = new QShortcut(QKeySequence::Copy, ui->plotWidget, nullptr, nullptr, Qt::WidgetShortcut);
     connect(shortcutCopy, SIGNAL(activated()), this, SLOT(copy()));
 
@@ -193,20 +199,8 @@ void PlotDock::updatePlot(SqliteTableModel* model, BrowseDataTableSettings* sett
     ui->plotWidget->xAxis->setLabel(QString());
     ui->plotWidget->yAxis->setLabel(QString());
 
-    ui->buttonLoadAllData->setEnabled(false);
-    ui->buttonLoadAllData->setStyleSheet("");
-    ui->buttonLoadAllData->setToolTip(tr("Load all data and redraw plot"));
-
     if(xitem)
     {
-        // Warn user if not all data has been fetched and hint about the button for loading all the data
-        if (m_currentTableSettings->plotYAxes.count() && model && model->canFetchMore()) {
-            ui->buttonLoadAllData->setEnabled(true);
-            ui->buttonLoadAllData->setStyleSheet("color: white; background-color: rgb(255, 102, 102)");
-            ui->buttonLoadAllData->setToolTip(tr("Load all data and redraw plot.\n"
-                                                 "Warning: not all data has been fetched from the table yet due to the partial fetch mechanism."));
-            QToolTip::showText(ui->buttonLoadAllData->mapToGlobal(QPoint(0, 0)), ui->buttonLoadAllData->toolTip());
-        }
         // regain the model column index and the datatype
         // leading 16 bit are column index, the other 16 bit are the datatype
         // right now datatype is only important for X axis (date, non date)
@@ -241,11 +235,6 @@ void PlotDock::updatePlot(SqliteTableModel* model, BrowseDataTableSettings* sett
 
                 graph->setPen(QPen(item->backgroundColor(PlotColumnY)));
                 graph->setSelectable (QCP::stDataRange);
-                // Enable: click on items to select them, Ctrl+Click for multi-selection, mouse-wheel for zooming and mouse drag for
-                // changing the visible range.
-                // Select one axis for zoom and drag applying only to that orientation.
-                ui->plotWidget->setInteractions(QCP::iSelectPlottables | QCP::iMultiSelect | QCP::iRangeZoom | QCP::iRangeDrag | QCP::iSelectAxes);
-                ui->plotWidget->setSelectionRectMode(QCP::srmNone);
 
                 // prepare the data vectors for qcustomplot
                 // possible improvement might be a QVector subclass that directly
@@ -309,6 +298,19 @@ void PlotDock::updatePlot(SqliteTableModel* model, BrowseDataTableSettings* sett
         ui->plotWidget->yAxis->setLabel(yAxisLabels.join("|"));
     }
     ui->plotWidget->replot();
+
+    // Warn user if not all data has been fetched and hint about the button for loading all the data
+    if (ui->plotWidget->graphCount() > 0 && model->canFetchMore()) {
+        ui->buttonLoadAllData->setEnabled(true);
+        ui->buttonLoadAllData->setStyleSheet("color: white; background-color: rgb(255, 102, 102)");
+        ui->buttonLoadAllData->setToolTip(tr("Load all data and redraw plot.\n"
+                                             "Warning: not all data has been fetched from the table yet due to the partial fetch mechanism."));
+        QToolTip::showText(ui->buttonLoadAllData->mapToGlobal(QPoint(0, 0)), ui->buttonLoadAllData->toolTip());
+    } else {
+        ui->buttonLoadAllData->setEnabled(false);
+        ui->buttonLoadAllData->setStyleSheet("");
+        ui->buttonLoadAllData->setToolTip(tr("Load all data and redraw plot"));
+    }
 }
 
 void PlotDock::on_treePlotColumns_itemChanged(QTreeWidgetItem* changeitem, int column)