Fix Preview button on filters dialog

Now unchecking the preview button will redraw the sprite editor and the
color palette to show their original state.

src/app/commands/filters/filter_manager_impl.cpp

@@ -311,10 +311,8 @@ void FilterManagerImpl::flush()
     Editor* editor = current_editor;
 
     // Redraw the color palette
-    if (m_nextRowToFlush == 0 && paletteHasChanged()) {
-      set_current_palette(getNewPalette(), false);
-      ColorBar::instance()->invalidate();
-    }
+    if (m_nextRowToFlush == 0 && paletteHasChanged())
+      redrawColorPalette();
 
     // We expand the region one pixel at the top and bottom of the
     // region [m_row,m_nextRowToFlush) to be updated on the screen to
@@ -342,6 +340,17 @@ void FilterManagerImpl::flush()
   }
 }
 
+void FilterManagerImpl::disablePreview()
+{
+  current_editor->invalidate();
+
+  // Redraw the color bar in case the filter modified the palette.
+  if (paletteHasChanged()) {
+    restoreSpritePalette();
+    redrawColorPalette();
+  }
+}
+
 const void* FilterManagerImpl::getSourceAddress()
 {
   return m_src->getPixelAddress(m_bounds.x, m_bounds.y+m_row);
@@ -453,6 +462,12 @@ void FilterManagerImpl::restoreSpritePalette()
     m_site.sprite()->setPalette(m_oldPalette.get(), false);
 }
 
+void FilterManagerImpl::redrawColorPalette()
+{
+  set_current_palette(getNewPalette(), false);
+  ColorBar::instance()->invalidate();
+}
+
 bool FilterManagerImpl::isMaskActive() const
 {
   return static_cast<const app::Document*>(m_site.document())

src/app/commands/filters/filter_manager_impl.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2001-2017  David Capello
+// Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -96,6 +96,8 @@ namespace app {
     // Updates the current editor to show the progress of the preview.
     void flush();
 
+    void disablePreview();
+
     // FilterManager implementation
     const void* getSourceAddress() override;
     void* getDestinationAddress() override;
@@ -120,8 +122,12 @@ namespace app {
     void apply();
     void applyToCel(doc::Cel* cel);
     bool updateBounds(doc::Mask* mask);
+
+    // Returns true if the palette was changed (true when the filter
+    // modifies the palette).
     bool paletteHasChanged();
     void restoreSpritePalette();
+    void redrawColorPalette();
 
     Context* m_context;
     doc::Site m_site;

src/app/commands/filters/filter_preview.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2001-2017  David Capello
+// Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -40,6 +40,21 @@ FilterPreview::~FilterPreview()
   stop();
 }
 
+void FilterPreview::setEnablePreview(bool state)
+{
+  if (state) {
+    current_editor->renderEngine().setPreviewImage(
+      m_filterMgr->layer(),
+      m_filterMgr->frame(),
+      m_filterMgr->destinationImage(),
+      m_filterMgr->position(),
+      static_cast<doc::LayerImage*>(m_filterMgr->layer())->blendMode());
+  }
+  else {
+    current_editor->renderEngine().removePreviewImage();
+  }
+}
+
 void FilterPreview::stop()
 {
   {
@@ -77,16 +92,11 @@ bool FilterPreview::onProcessMessage(Message* msg)
   switch (msg->type()) {
 
     case kOpenMessage:
-      current_editor->renderEngine().setPreviewImage(
-        m_filterMgr->layer(),
-        m_filterMgr->frame(),
-        m_filterMgr->destinationImage(),
-        m_filterMgr->position(),
-        static_cast<doc::LayerImage*>(m_filterMgr->layer())->blendMode());
+      setEnablePreview(true);
       break;
 
     case kCloseMessage:
-      current_editor->renderEngine().removePreviewImage();
+      setEnablePreview(false);
 
       // Stop the preview timer.
       m_timer.stop();

src/app/commands/filters/filter_preview.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2001-2017  David Capello
+// Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -24,6 +24,8 @@ namespace app {
     FilterPreview(FilterManagerImpl* filterMgr);
     ~FilterPreview();
 
+    void setEnablePreview(bool state);
+
     void stop();
     void restartPreview();
 

src/app/commands/filters/filter_window.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2001-2017  David Capello
+// Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -10,11 +10,13 @@
 
 #include "app/commands/filters/filter_window.h"
 
-#include "base/bind.h"
 #include "app/commands/filters/filter_manager_impl.h"
 #include "app/commands/filters/filter_worker.h"
 #include "app/ini_file.h"
+#include "app/modules/editors.h"
 #include "app/modules/gui.h"
+#include "app/ui/editor/editor.h"
+#include "base/bind.h"
 
 namespace app {
 
@@ -106,7 +108,7 @@ bool FilterWindow::doModal()
 
   // Did the user press OK?
   if (closer() == &m_okButton) {
-    m_preview.stop();
+    stopPreview();
 
     // Apply the filter in background
     start_filter_worker(m_filterMgr);
@@ -121,8 +123,13 @@ bool FilterWindow::doModal()
 
 void FilterWindow::restartPreview()
 {
-  if (m_showPreview.isSelected())
+  bool state = m_showPreview.isSelected();
+  m_preview.setEnablePreview(state);
+
+  if (state)
     m_preview.restartPreview();
+  else
+    stopPreview();
 }
 
 void FilterWindow::setNewTarget(Target target)
@@ -146,6 +153,11 @@ void FilterWindow::onCancel(Event& ev)
 void FilterWindow::onShowPreview(Event& ev)
 {
   restartPreview();
+
+  // If the preview was disabled just redraw the current editor in its
+  // original state.
+  if (!m_showPreview.isSelected())
+    m_filterMgr->disablePreview();
 }
 
 // Called when the user changes the target-buttons.