changeset 1337:3dcd83595bc8 3.0-integration

Make writable model updating explicit rather than essentially an arbitrary hidden accident

--- a/data/model/WritableWaveFileModel.cpp	Wed Jan 04 12:05:14 2017 +0000
+++ b/data/model/WritableWaveFileModel.cpp	Wed Jan 04 14:22:39 2017 +0000
@@ -120,30 +120,27 @@
 #endif
 
     if (!m_writer->writeSamples(samples, count)) {
-        cerr << "ERROR: WritableWaveFileModel::addSamples: writer failed: " << m_writer->getError() << endl;
+        SVCERR << "ERROR: WritableWaveFileModel::addSamples: writer failed: " << m_writer->getError() << endl;
         return false;
     }
 
     m_frameCount += count;
 
-    static int updateCounter = 0;
-
     if (m_reader && m_reader->getChannelCount() == 0) {
-#ifdef DEBUG_WRITABLE_WAVE_FILE_MODEL
-        SVDEBUG << "WritableWaveFileModel::addSamples(" << count << "): calling updateFrameCount (initial)" << endl;
-#endif
         m_reader->updateFrameCount();
-    } else if (++updateCounter == 100) {
-#ifdef DEBUG_WRITABLE_WAVE_FILE_MODEL
-        SVDEBUG << "WritableWaveFileModel::addSamples(" << count << "): calling updateFrameCount (periodic)" << endl;
-#endif
-        if (m_reader) m_reader->updateFrameCount();
-        updateCounter = 0;
     }
 
     return true;
 }
 
+void
+WritableWaveFileModel::updateModel()
+{
+    if (m_reader) {
+        m_reader->updateFrameCount();
+    }
+}
+
 bool
 WritableWaveFileModel::isOK() const
 {

--- a/data/model/WritableWaveFileModel.h	Wed Jan 04 12:05:14 2017 +0000
+++ b/data/model/WritableWaveFileModel.h	Wed Jan 04 14:22:39 2017 +0000
@@ -33,13 +33,36 @@
 
     /**
      * Call addSamples to append a block of samples to the end of the
-     * file.  Caller should also call setWriteProportion() to update
-     * the progress of this file, if it has a known end point, and
-     * should call writeComplete() when the file has been written.
+     * file.
+     *
+     * This function only appends the samples to the file being
+     * written; it does not update the model's view of the samples in
+     * that file. That is, it updates the file on disc but the model
+     * itself does not change its content. This is because re-reading
+     * the file to update the model may be more expensive than adding
+     * the samples in the first place. If you are writing small
+     * numbers of samples repeatedly, you probably only want the model
+     * to update periodically rather than after every write.
+     *
+     * Call updateModel() periodically to tell the model to update its
+     * own view of the samples in the file being written.
+     *
+     * Call setWriteProportion() periodically if the file being
+     * written has known duration and you want the model to be able to
+     * report the write progress as a percentage.
+     *
+     * Call writeComplete() when the file has been completely written.
      */
     virtual bool addSamples(const float *const *samples, sv_frame_t count);
 
     /**
+     * Tell the model to update its own (read) view of the (written)
+     * file. May cause modelChanged() and modelChangedWithin() to be
+     * emitted. See the comment to addSamples above for rationale.
+     */
+    void updateModel();
+    
+    /**
      * Set the proportion of the file which has been written so far,
      * as a percentage. This may be used to indicate progress.
      *
@@ -56,7 +79,7 @@
 
     /**
      * Indicate that writing is complete. You should call this even if
-     * you have never called setWriteProportion().
+     * you have never called setWriteProportion() or updateModel().
      */
     void writeComplete();