Another update to the calculator:

1) Add buttons to clear/save the history (saves as plaintext to a file)
2) Tag each result with a number (#1), and allow the usage of #<number> to recall a history item
3) When recalling history, see if the result looks like it was rounded using the double->text routine for display. If so, substitute the equation, otherwise just use the result (tries to ensure no rounding error-continuity by using previous results).

4 files changed, 102 insertions, 17 deletions

diff --git a/src-qt5/desktop-utils/lumina-calculator/EqValidator.h b/src-qt5/desktop-utils/lumina-calculator/EqValidator.h
index 8218efdf..ab9bcc22 100644
--- a/src-qt5/desktop-utils/lumina-calculator/EqValidator.h
+++ b/src-qt5/desktop-utils/lumina-calculator/EqValidator.h
@@ -7,10 +7,10 @@
 #ifndef _LUMINA_CALCULATOR_VALIDATOR_H
 #define _LUMINA_CALCULATOR_VALIDATOR_H
 
-#define VALIDCHARS QString("x*+-/^%eE().0123456789")
+#define VALIDCHARS QString("x*+-/^%eE().0123456789#")
 #define NOSTARTCHARS QString("x*/^%)eE.")
-#define NOENDCHARS QString("x*/^(eE.")
-#define NOCHANGE QString("().")
+#define NOENDCHARS QString("x*/^(eE.#")
+#define NOCHANGE QString("().#")
 
 #include <QValidator>
 #include <QString>
diff --git a/src-qt5/desktop-utils/lumina-calculator/mainUI.cpp b/src-qt5/desktop-utils/lumina-calculator/mainUI.cpp
index b26acb73..2f38abae 100644
--- a/src-qt5/desktop-utils/lumina-calculator/mainUI.cpp
+++ b/src-qt5/desktop-utils/lumina-calculator/mainUI.cpp
@@ -9,7 +9,9 @@
 
 #include <QDebug>
 #include <QClipboard>
+#include <QFileDialog>
 
+#include <LuminaUtils.h>
 #include <LuminaXDG.h>
 #include "EqValidator.h"
 
@@ -41,6 +43,8 @@ mainUI::mainUI() : QMainWindow(), ui(new Ui::mainUI()){
   connect(ui->button_Percent, SIGNAL(clicked()), this, SLOT(captureButtonPercent()) );
   connect(ui->button_Equal, SIGNAL (clicked()), this, SLOT (start_calc()));
   connect(ui->list_results, SIGNAL(itemClicked(QListWidgetItem*)), this, SLOT(insert_history(QListWidgetItem*)) );
+  connect(ui->tool_history_clear, SIGNAL(clicked()), ui->list_results, SLOT(clear()) );
+  connect(ui->tool_history_save, SIGNAL(clicked()), this, SLOT(saveHistory()) );
   //connect(ui->list_results, SIGNAL(itemRightClicked(QListWidgetItem*)), this, SLOT(copt_to_clipboard(QListWidgetItem*)) );
   this->setWindowTitle(tr("Calculator"));
   updateIcons();
@@ -54,6 +58,8 @@ mainUI::~mainUI(){
 void mainUI::updateIcons(){
   this->setWindowIcon( LXDG::findIcon("accessories-calculator","") );
   ui->tool_clear->setIcon( LXDG::findIcon("edit-clear-locationbar-rtl","dialog-cancel") );
+  ui->tool_history_clear->setIcon( LXDG::findIcon("document-close","edit-clear-list") );
+  ui->tool_history_save->setIcon( LXDG::findIcon("document-save-as","edit-copy") );
 }
 
 void mainUI::start_calc(){
@@ -62,8 +68,8 @@ void mainUI::start_calc(){
     eq.replace("%","/(100)");
   double result = strToNumber(eq);
   if(result!=result){ return; } //bad calculation - NaN's values are special in that they don't equal itself
-  QString res = "%1 \t= [ %2 ]";
-  ui->list_results->addItem(res.arg(QString::number(result), ui->line_eq->text()));
+  QString res = "[#%1]  %2 \t= [ %3 ]";
+  ui->list_results->addItem(res.arg(QString::number(ui->list_results->count()+1), QString::number(result), ui->line_eq->text()));
   ui->list_results->scrollToItem( ui->list_results->item( ui->list_results->count()-1) );
   ui->line_eq->clear();
 }
@@ -92,7 +98,7 @@ void mainUI::captureButtonDecimal(){ ui->line_eq->insert(ui->button_Decimal->tex
 void mainUI::captureButtonPercent(){ ui->line_eq->insert(ui->button_Percent->text()); }
 
 void mainUI::insert_history(QListWidgetItem *it){
-  QString txt = it->text().section("[",1,-1).section("]",0,0).simplified();
+  QString txt = it->text().section("[",-1).section("]",0,0).simplified();
   ui->line_eq->insert("("+txt+")");
 }
 
@@ -104,12 +110,20 @@ void mainUI::copy_to_clipboard(QListWidgetItem *it){
 void mainUI::checkInput(const QString &str){
   if(str.length()==1 && ui->list_results->count()>0){
     if(OPS.contains(str)){ 
-      QString lastresult = ui->list_results->item( ui->list_results->count()-1)->text().section("=",0,0).simplified();
+      QString lastresult = ui->list_results->item( ui->list_results->count()-1)->text().section("]",0,0).section("[",-1).simplified();
       ui->line_eq->setText( lastresult+str);
     }
   }
 }
 
+void mainUI::saveHistory(){
+  QStringList history;
+  for(int i=0; i<ui->list_results->count(); i++){ history << ui->list_results->item(i)->text(); }
+  QString file = QFileDialog::getSaveFileName(this, tr("Save Calculator History"), QDir::homePath() );
+  if(file.section(".",-1).isEmpty()){ file.append(".txt"); }
+  LUtils::writeFile(file, history, true);
+}
+
 // =====================
 //   PRIVATE FUNCTIONS
 // =====================
@@ -126,6 +140,23 @@ double mainUI::performOperation(double LHS, double RHS, QChar symbol){
 }
 
 double mainUI::strToNumber(QString str){
+  //Look for history replacements first
+  while(str.contains("#")){
+    int index = str.indexOf("#");
+    int num = -1; //history number
+    for(int i=index+1; i<str.length(); i++){
+      if(!str[i].isNumber() ||  i==(str.length()-1) ){
+        if(!str[i].isNumber()){ i--; } //go back to the last valid char
+        //qDebug() << "Replace History:" << str << index << i << str.mid(index+1, i-index);
+        num = str.mid(index+1, i-index).toInt();
+        //qDebug() << " H number:" << num;
+        str.replace(index, i-index+1, getHistory(num));
+        //qDebug() << " After Replace:" << str;
+        break; //finished with this history item
+      }
+    }
+    if(num<1){ return BADVALUE; } //could not perform substitution
+  }
   //Look for perentheses first
   //qDebug() << "String to Number: " << str;
   if(str.indexOf("(")>=0){
@@ -177,3 +208,19 @@ double mainUI::strToNumber(QString str){
   //qDebug() << " - Found Number:" << str << str.toDouble();
   return str.toDouble();
 }
+
+QString mainUI::getHistory(int number){
+  if(number <1 || number > ui->list_results->count()){
+    //use the last history item
+    number = ui->list_results->count();
+  }
+  QString ans = ui->list_results->item(number-1)->text().section("=",0,0).section("]",-1).simplified();
+  QString eq = ui->list_results->item(number-1)->text().section("[",-1).section("]",0,0).simplified();
+  //See if the text answer is accurate enough (does not look rounded)
+  if(ans.length()<7){ 
+    return ("("+ans+")"); //short enough answer that it was probably not rounded
+  }else{
+    //need to re-calculate the last equation instead for exact result
+    return ("("+eq+")");
+  }
+}
diff --git a/src-qt5/desktop-utils/lumina-calculator/mainUI.h b/src-qt5/desktop-utils/lumina-calculator/mainUI.h
index cf09801e..9dc28f3c 100644
--- a/src-qt5/desktop-utils/lumina-calculator/mainUI.h
+++ b/src-qt5/desktop-utils/lumina-calculator/mainUI.h
@@ -50,9 +50,12 @@ private slots:
 	void copy_to_clipboard(QListWidgetItem *it);
 	void checkInput(const QString&);
 
+	void saveHistory();
+
 private:
 	Ui::mainUI *ui;
 	double performOperation(double LHS, double RHS, QChar symbol);
 	double strToNumber(QString str); //this is highly-recursive
+	QString getHistory(int number = -1);
 };
 #endif
diff --git a/src-qt5/desktop-utils/lumina-calculator/mainUI.ui b/src-qt5/desktop-utils/lumina-calculator/mainUI.ui
index 7a0ccfed..4ff5c421 100644
--- a/src-qt5/desktop-utils/lumina-calculator/mainUI.ui
+++ b/src-qt5/desktop-utils/lumina-calculator/mainUI.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>171</width>
-    <height>258</height>
+    <width>204</width>
+    <height>260</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -50,14 +50,49 @@
       <widget class="QWidget" name="layoutWidget">
        <layout class="QVBoxLayout" name="verticalLayout">
         <item>
-         <widget class="QListWidget" name="list_results">
-          <property name="focusPolicy">
-           <enum>Qt::NoFocus</enum>
-          </property>
-          <property name="selectionMode">
-           <enum>QAbstractItemView::NoSelection</enum>
-          </property>
-         </widget>
+         <layout class="QHBoxLayout" name="horizontalLayout_2">
+          <item>
+           <widget class="QListWidget" name="list_results">
+            <property name="focusPolicy">
+             <enum>Qt::NoFocus</enum>
+            </property>
+            <property name="selectionMode">
+             <enum>QAbstractItemView::NoSelection</enum>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <layout class="QVBoxLayout" name="verticalLayout_3">
+            <item>
+             <widget class="QToolButton" name="tool_history_clear">
+              <property name="text">
+               <string notr="true"/>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QToolButton" name="tool_history_save">
+              <property name="text">
+               <string notr="true"/>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <spacer name="verticalSpacer">
+              <property name="orientation">
+               <enum>Qt::Vertical</enum>
+              </property>
+              <property name="sizeHint" stdset="0">
+               <size>
+                <width>20</width>
+                <height>40</height>
+               </size>
+              </property>
+             </spacer>
+            </item>
+           </layout>
+          </item>
+         </layout>
         </item>
         <item>
          <layout class="QHBoxLayout" name="horizontalLayout">