From d126e86e81f2249f73b2e690ddec6899c3494f3b Mon Sep 17 00:00:00 2001
From: Martin Kleusberg <mkleusberg@gmail.com>
Date: Sun, 22 Oct 2017 18:29:54 +0200
Subject: [PATCH] Make sure to not re-run the query if the filters haven't
 changed

When changing between the filter line edits in the Browse Data tab, make
sure to only re-run the SQL query if the value of the filter line edits
have actually changed.

See issue #1187.
---
 src/FilterLineEdit.cpp | 12 ++++++++++--
 src/FilterLineEdit.h   |  1 +
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/FilterLineEdit.cpp b/src/FilterLineEdit.cpp
index 38e7a0fc..d00ad628 100644
--- a/src/FilterLineEdit.cpp
+++ b/src/FilterLineEdit.cpp
@@ -30,8 +30,16 @@ void FilterLineEdit::delayedSignalTimerTriggered()
     // Stop the timer first to avoid triggering in intervals
     delaySignalTimer->stop();
 
-    // Emit the delayed signal using the current value
-    emit delayedTextChanged(text());
+    // Only emit text changed signal if the text has actually changed in comparison to the last emitted signal. This is necessary
+    // because this method is also called whenever the line edit loses focus and not only when its text has definitely been changed.
+    if(text() != lastValue)
+    {
+        // Emit the delayed signal using the current value
+        emit delayedTextChanged(text());
+
+        // Remember this value for the next time
+        lastValue = text();
+    }
 }
 
 void FilterLineEdit::keyReleaseEvent(QKeyEvent* event)
diff --git a/src/FilterLineEdit.h b/src/FilterLineEdit.h
index b1d9fe13..fb803990 100644
--- a/src/FilterLineEdit.h
+++ b/src/FilterLineEdit.h
@@ -31,6 +31,7 @@ private:
     QList<FilterLineEdit*>* filterList;
     int columnNumber;
     QTimer* delaySignalTimer;
+    QString lastValue;
 };
 
 #endif