Show Details widget doesn't follow content during install.

Now also keeps the position if we have scrolled somewhere.

Task-number: QTIFW-353
Change-Id: I58e90592df3d8d4589b5e577366c251e501900d9
Reviewed-by: Niels Weber <niels.weber@digia.com>

3 files changed, 29 insertions, 11 deletions

diff --git a/src/libs/installer/lazyplaintextedit.cpp b/src/libs/installer/lazyplaintextedit.cpp
index c0857458a..93a090e96 100644
--- a/src/libs/installer/lazyplaintextedit.cpp
+++ b/src/libs/installer/lazyplaintextedit.cpp
@@ -57,10 +57,12 @@ void LazyPlainTextEdit::timerEvent(QTimerEvent *event)
         killTimer(m_timerId);
         m_timerId = 0;
         m_cachedOutput.chop(1); //removes the last \n
-        if (!m_cachedOutput.isEmpty())
+        if (!m_cachedOutput.isEmpty()) {
             appendPlainText(m_cachedOutput);
-        horizontalScrollBar()->setValue( 0 );
-        m_cachedOutput.clear();
+            updateCursor(TextCursorPosition::Keep);
+            horizontalScrollBar()->setValue(0);
+            m_cachedOutput.clear();
+        }
     }
 }
 
@@ -81,7 +83,6 @@ void LazyPlainTextEdit::clear()
     QPlainTextEdit::clear();
 }
 
-
 void LazyPlainTextEdit::setVisible(bool visible)
 {
     if (m_timerId) {
@@ -93,4 +94,21 @@ void LazyPlainTextEdit::setVisible(bool visible)
         m_timerId = startTimer(INTERVAL);
 
     QPlainTextEdit::setVisible(visible);
+    updateCursor(TextCursorPosition::Keep);
+}
+
+void LazyPlainTextEdit::updateCursor(TextCursorPosition position)
+{
+    QTextCursor cursor = textCursor();
+    if ((position == TextCursorPosition::ForceEnd) || cursor.atEnd()) {
+        // Workaround for height calculation issue if scrollbar is set to Qt::ScrollBarAsNeeded.
+        Qt::ScrollBarPolicy policy = horizontalScrollBarPolicy();
+        setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn); // enforce always on
+
+        cursor.movePosition(QTextCursor::End);
+        setTextCursor(cursor);
+        ensureCursorVisible();
+
+        setHorizontalScrollBarPolicy(policy); // but reset once we updated the cursor position
+    }
 }
diff --git a/src/libs/installer/lazyplaintextedit.h b/src/libs/installer/lazyplaintextedit.h
index 34651a36b..06cf45f0a 100644
--- a/src/libs/installer/lazyplaintextedit.h
+++ b/src/libs/installer/lazyplaintextedit.h
@@ -48,7 +48,12 @@ class LazyPlainTextEdit : public QPlainTextEdit
 {
     Q_OBJECT
 public:
+    enum struct TextCursorPosition {
+        Keep,
+        ForceEnd
+    };
     explicit LazyPlainTextEdit(QWidget *parent = 0);
+    void updateCursor(TextCursorPosition position);
 
 public slots:
     void append(const QString &text);
diff --git a/src/libs/installer/performinstallationform.cpp b/src/libs/installer/performinstallationform.cpp
index 211d8176e..5480b397a 100644
--- a/src/libs/installer/performinstallationform.cpp
+++ b/src/libs/installer/performinstallationform.cpp
@@ -1,6 +1,6 @@
 /**************************************************************************
 **
-** Copyright (C) 2012-2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2012-2014 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the Qt Installer Framework.
@@ -149,10 +149,6 @@ void PerformInstallationForm::toggleDetails()
 {
     const bool willShow = !isShowingDetails();
     m_detailsButton->setText(willShow ? tr("&Hide Details") : tr("&Show Details"));
-
-    if (willShow)
-        scrollDetailsToTheEnd();
-
     m_detailsBrowser->setVisible(willShow);
     emit showDetailsChanged();
 }
@@ -188,8 +184,7 @@ void PerformInstallationForm::setDetailsButtonEnabled(bool enable)
 
 void PerformInstallationForm::scrollDetailsToTheEnd()
 {
-    m_detailsBrowser->horizontalScrollBar()->setValue(0);
-    m_detailsBrowser->verticalScrollBar()->setValue(m_detailsBrowser->verticalScrollBar()->maximum());
+    m_detailsBrowser->updateCursor(LazyPlainTextEdit::TextCursorPosition::ForceEnd);
 }
 
 bool PerformInstallationForm::isShowingDetails() const