CursesDialog: resolve clang-tidy warnings

Fixes:

  - unnecessary bool expression (cmCursesMainForm)
  - removes a duplicate if/else branch (RegexExplorer)
  - collapses redundant if/else branch logic (CMakeSetupDialog and
    cmCursesStringWidget)

Source/CursesDialog/cmCursesMainForm.cxx

@@ -853,11 +853,7 @@ void cmCursesMainForm::HandleInput()
       }
       // switch advanced on/off
       else if (key == 't') {
-        if (this->AdvancedMode) {
-          this->AdvancedMode = false;
-        } else {
-          this->AdvancedMode = true;
-        }
+        this->AdvancedMode = !this->AdvancedMode;
         getmaxyx(stdscr, y, x);
         this->RePost();
         this->Render(1, 1, x, y);

Source/CursesDialog/cmCursesStringWidget.cxx

@@ -105,12 +105,10 @@ bool cmCursesStringWidget::HandleInput(int& key, cmCursesMainForm* fm,
     if (!this->InEdit && (key != 10 && key != KEY_ENTER && key != 'i')) {
       return false;
     }
-    // enter edit with return and i (vim binding)
-    if (!this->InEdit && (key == 10 || key == KEY_ENTER || key == 'i')) {
-      this->OnReturn(fm, w);
-    }
-    // leave edit with return (but not i -- not a toggle)
-    else if (this->InEdit && (key == 10 || key == KEY_ENTER)) {
+    // toggle edit with return
+    if ((key == 10 || key == KEY_ENTER)
+        // enter edit with i (and not-edit mode)
+        || (!this->InEdit && key == 'i')) {
       this->OnReturn(fm, w);
     } else if (key == KEY_DOWN || key == ctrl('n') || key == KEY_UP ||
                key == ctrl('p') || key == KEY_NPAGE || key == ctrl('d') ||

Source/QtDialog/CMakeSetupDialog.cxx

@@ -1060,14 +1060,7 @@ void CMakeSetupDialog::enterState(CMakeSetupDialog::State s)
     this->GenerateAction->setEnabled(false);
     this->OpenProjectButton->setEnabled(false);
     this->GenerateButton->setText(tr("&Stop"));
-  } else if (s == ReadyConfigure) {
-    this->setEnabledState(true);
-    this->GenerateButton->setEnabled(true);
-    this->GenerateAction->setEnabled(true);
-    this->ConfigureButton->setEnabled(true);
-    this->ConfigureButton->setText(tr("&Configure"));
-    this->GenerateButton->setText(tr("&Generate"));
-  } else if (s == ReadyGenerate) {
+  } else if (s == ReadyConfigure || s == ReadyGenerate) {
     this->setEnabledState(true);
     this->GenerateButton->setEnabled(true);
     this->GenerateAction->setEnabled(true);

Source/QtDialog/RegexExplorer.cxx

@@ -147,9 +147,6 @@ bool RegexExplorer::stripEscapes(std::string& source)
       } else if (nextc == 'n') {
         result.append(1, '\n');
         in++;
-      } else if (nextc == 't') {
-        result.append(1, '\t');
-        in++;
       } else if (isalnum(nextc) || nextc == '\0') {
         return false;
       } else {