Centralize zoom-to-fit code.

Fixes a bunch of errors:
- libedit and libbrowser would zoom to bounding box but centre on canvas
- libedit, libbrowser and gerbview didn’t take the scroll bars into account
- pcbnew didn’t take scroll bars into account or apply the 10% margin
- appending a board file would re-centre, but not re-zoom

Fixes: lp:1504302
* https://bugs.launchpad.net/kicad/+bug/1504302

common/tool/common_tools.cpp

@@ -107,6 +107,7 @@ int COMMON_TOOLS::ZoomFitScreen( const TOOL_EVENT& aEvent )
     KIGFX::VIEW* view = getView();
     EDA_DRAW_PANEL_GAL* galCanvas = m_frame->GetGalCanvas();
     EDA_ITEM* model = getModel<EDA_ITEM>();
+    EDA_BASE_FRAME* frame = getEditFrame<EDA_BASE_FRAME>();
 
     BOX2I bBox = model->ViewBBox();
     VECTOR2D scrollbarSize = VECTOR2D( galCanvas->GetSize() - galCanvas->GetClientSize() );
@@ -121,7 +122,18 @@ int COMMON_TOOLS::ZoomFitScreen( const TOOL_EVENT& aEvent )
     double scale = view->GetScale() / std::max( fabs( vsize.x / screenSize.x ),
                                                 fabs( vsize.y / screenSize.y ) );
 
-    view->SetScale( scale );
+    // Reserve a 10% margin around component bounding box.
+    double margin_scale_factor = 1.1;
+
+    // Leave 20% for library editors & viewers
+    if( frame->IsType( FRAME_PCB_MODULE_VIEWER ) || frame->IsType( FRAME_PCB_MODULE_VIEWER_MODAL )
+            || frame->IsType( FRAME_SCH_VIEWER ) || frame->IsType( FRAME_SCH_VIEWER_MODAL )
+            || frame->IsType( FRAME_SCH_LIB_EDITOR ) || frame->IsType( FRAME_PCB_MODULE_EDITOR ) )
+    {
+        margin_scale_factor = 1.2;
+    }
+
+    view->SetScale( scale / margin_scale_factor );
     view->SetCenter( bBox.Centre() );
 
     // Take scrollbars into account

common/zoom.cpp

@@ -78,6 +78,27 @@ void EDA_DRAW_FRAME::RedrawScreen2( const wxPoint& posBefore )
 }
 
 
+// Factor out the calculation portion of the various BestZoom() implementations.
+//
+// Note that like it's forerunners this routine has an intentional side-effect: it
+// sets the scroll centre position.  While I'm not happy about that, it's probably
+// not worth fixing as its days are numbered (GAL canvases use a different method).
+double EDA_DRAW_FRAME::bestZoom( double sizeX, double sizeY, double scaleFactor, wxPoint centre )
+{
+    double bestzoom = std::max( sizeX * scaleFactor / (double) m_canvas->GetClientSize().x,
+                                sizeY * scaleFactor / (double) m_canvas->GetClientSize().y );
+
+    // Take scrollbars into account
+    DSIZE scrollbarSize = m_canvas->GetSize() - m_canvas->GetClientSize();
+    centre.x -= int( bestzoom * scrollbarSize.x / 2.0 );
+    centre.y -= int( bestzoom * scrollbarSize.y / 2.0 );
+
+    SetScrollCenterPosition( centre );
+
+    return bestzoom;
+}
+
+
 void EDA_DRAW_FRAME::Zoom_Automatique( bool aWarpPointer )
 {
     BASE_SCREEN* screen = GetScreen();

eeschema/lib_edit_frame.cpp

@@ -357,49 +357,25 @@ void LIB_EDIT_FRAME::OnCloseWindow( wxCloseEvent& Event )
 
 double LIB_EDIT_FRAME::BestZoom()
 {
-    /* Please, note: wxMSW before version 2.9 seems have
-     * problems with zoom values < 1 ( i.e. userscale > 1) and needs to be patched:
-     * edit file <wxWidgets>/src/msw/dc.cpp
-     * search for line static const int VIEWPORT_EXTENT = 1000;
-     * and replace by static const int VIEWPORT_EXTENT = 10000;
-     */
-    int      dx, dy;
+    LIB_PART*  part = GetCurPart();
+    double     defaultLibraryZoom = 7.33;
 
-    LIB_PART*      part = GetCurPart();
-
-    if( part )
-    {
-        EDA_RECT boundingBox = part->GetUnitBoundingBox( m_unit, m_convert );
-
-        dx = boundingBox.GetWidth();
-        dy = boundingBox.GetHeight();
-        SetScrollCenterPosition( wxPoint( 0, 0 ) );
-    }
-    else
+    if( !part )
     {
-        const PAGE_INFO& pageInfo = GetScreen()->GetPageSettings();
-
-        dx = pageInfo.GetSizeIU().x;
-        dy = pageInfo.GetSizeIU().y;
-
         SetScrollCenterPosition( wxPoint( 0, 0 ) );
+        return defaultLibraryZoom;
     }
 
-    wxSize size = m_canvas->GetClientSize();
-
-    // Reserve a 10% margin around component bounding box.
-    double margin_scale_factor = 0.8;
-    double zx =(double) dx / ( margin_scale_factor * (double)size.x );
-    double zy = (double) dy / ( margin_scale_factor * (double)size.y );
+    EDA_RECT boundingBox = part->GetUnitBoundingBox( m_unit, m_convert );
 
-    double bestzoom = std::max( zx, zy );
+    double  sizeX  = (double) boundingBox.GetWidth();
+    double  sizeY  = (double) boundingBox.GetHeight();
+    wxPoint centre = boundingBox.Centre();
 
-    // keep it >= minimal existing zoom (can happen for very small components
-    // for instance when starting a new component
-    if( bestzoom  < GetScreen()->m_ZoomList[0] )
-        bestzoom  = GetScreen()->m_ZoomList[0];
+    // Reserve a 20% margin around component bounding box.
+    double margin_scale_factor = 1.2;
 
-    return bestzoom;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre);
 }
 
 

eeschema/sch_edit_frame.cpp

@@ -435,9 +435,6 @@ SCH_EDIT_FRAME::SCH_EDIT_FRAME( KIWAY* aKiway, wxWindow* aParent ):
 
     m_auimgr.Update();
 
-    // Now Drawpanel is sized, we can use BestZoom to show the component (if any)
-    GetScreen()->SetZoom( BestZoom() );
-
     Zoom_Automatique( false );
 
     // Net list generator
@@ -718,25 +715,15 @@ void SCH_EDIT_FRAME::OnCloseWindow( wxCloseEvent& aEvent )
 
 double SCH_EDIT_FRAME::BestZoom()
 {
-    int    dx, dy;
-    wxSize size;
-
-    dx = GetScreen()->GetPageSettings().GetWidthIU();
-    dy = GetScreen()->GetPageSettings().GetHeightIU();
-
-    size = m_canvas->GetClientSize();
-
-    // Reserve no margin because best zoom shows the full page
-    // and margins are already included in function that draws the sheet refernces
-    double margin_scale_factor = 1.0;
-    double zx =(double) dx / ( margin_scale_factor * (double)size.x );
-    double zy = (double) dy / ( margin_scale_factor * (double)size.y );
-
-    double bestzoom = std::max( zx, zy );
+    double  sizeX = (double) GetScreen()->GetPageSettings().GetWidthIU();
+    double  sizeY = (double) GetScreen()->GetPageSettings().GetHeightIU();
+    wxPoint centre( wxPoint( sizeX / 2, sizeY / 2 ) );
 
-    SetScrollCenterPosition( wxPoint( dx / 2, dy / 2 ) );
+    // The sheet boundary already affords us some margin, so add only an
+    // additional 5%.
+    double margin_scale_factor = 1.05;
 
-    return bestzoom;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre );
 }
 
 

eeschema/viewlib_frame.cpp

@@ -237,7 +237,7 @@ LIB_VIEW_FRAME::LIB_VIEW_FRAME( KIWAY* aKiway, wxWindow* aParent, FRAME_T aFrame
 
     // Now Drawpanel is sized, we can use BestZoom to show the component (if any)
 #ifdef USE_WX_GRAPHICS_CONTEXT
-    GetScreen()->SetZoom( BestZoom() );
+    GetScreen()->SetScalingFactor( BestZoom() );
 #else
     Zoom_Automatique( false );
 #endif
@@ -369,20 +369,13 @@ void LIB_VIEW_FRAME::OnUpdateElectricalType( wxUpdateUIEvent& aEvent )
 
 double LIB_VIEW_FRAME::BestZoom()
 {
-    /* Please, note: wxMSW before version 2.9 seems have
-     * problems with zoom values < 1 ( i.e. userscale > 1) and needs to be patched:
-     * edit file <wxWidgets>/src/msw/dc.cpp
-     * search for line static const int VIEWPORT_EXTENT = 1000;
-     * and replace by static const int VIEWPORT_EXTENT = 10000;
-     */
-
     LIB_PART*   part = NULL;
-    double      bestzoom = 16.0;      // default value for bestzoom
+    double      defaultLibraryZoom = 7.33;
 
     if( m_libraryName.IsEmpty() || m_entryName.IsEmpty() )
     {
         SetScrollCenterPosition( wxPoint( 0, 0 ) );
-        return bestzoom;
+        return defaultLibraryZoom;
     }
 
     LIB_ALIAS* alias = nullptr;
@@ -401,29 +394,19 @@ double LIB_VIEW_FRAME::BestZoom()
     if( !part )
     {
         SetScrollCenterPosition( wxPoint( 0, 0 ) );
-        return bestzoom;
+        return defaultLibraryZoom;
     }
 
-    wxSize size = m_canvas->GetClientSize();
-
     EDA_RECT boundingBox = part->GetUnitBoundingBox( m_unit, m_convert );
 
-    // Reserve a 10% margin around component bounding box.
-    double margin_scale_factor = 0.8;
-    double zx =(double) boundingBox.GetWidth() / ( margin_scale_factor * (double)size.x );
-    double zy = (double) boundingBox.GetHeight() / ( margin_scale_factor * (double)size.y);
-
-    // Calculates the best zoom
-    bestzoom = std::max( zx, zy );
-
-    // keep it >= minimal existing zoom (can happen for very small components
-    // like small power symbols
-    if( bestzoom  < GetScreen()->m_ZoomList[0] )
-        bestzoom  = GetScreen()->m_ZoomList[0];
+    double  sizeX  = (double) boundingBox.GetWidth();
+    double  sizeY  = (double) boundingBox.GetHeight();
+    wxPoint centre = boundingBox.Centre();
 
-    SetScrollCenterPosition( boundingBox.Centre() );
+    // Reserve a 20% margin around component bounding box.
+    double  margin_scale_factor = 1.2;
 
-    return bestzoom;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre );
 }
 
 

gerbview/gerbview_frame.cpp

@@ -361,24 +361,23 @@ bool GERBVIEW_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
 double GERBVIEW_FRAME::BestZoom()
 {
+    double   defaultGerberZoom = 1.0;
     EDA_RECT bbox = GetGerberLayout()->ComputeBoundingBox();
 
-    // gives a size to bbox (current page size), if no item in list
     if( bbox.GetWidth() == 0 || bbox.GetHeight() == 0 )
     {
-        wxSize pagesize = GetPageSettings().GetSizeMils();
-        bbox.SetSize( wxSize( Mils2iu( pagesize.x ), Mils2iu( pagesize.y ) ) );
+        SetScrollCenterPosition( wxPoint( 0, 0 ) );
+        return defaultGerberZoom;
     }
 
-    // Compute best zoom:
-    wxSize  size = m_canvas->GetClientSize();
-    double  x   = (double) bbox.GetWidth() / (double) size.x;
-    double  y   = (double) bbox.GetHeight() / (double) size.y;
-    double  best_zoom = std::max( x, y ) * 1.1;
+    double  sizeX = (double) bbox.GetWidth();
+    double  sizeY = (double) bbox.GetHeight();
+    wxPoint centre = bbox.Centre();
 
-    SetScrollCenterPosition( bbox.Centre() );
+    // Reserve no margin because GetGerberLayout()->ComputeBoundingBox() builds one in.
+    double margin_scale_factor = 1.0;
 
-    return best_zoom;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre );
 }
 
 

include/draw_frame.h

@@ -149,6 +149,8 @@ protected:
 
     void SetScreen( BASE_SCREEN* aScreen )  { m_currentScreen = aScreen; }
 
+    double bestZoom( double sizeX, double sizeY, double scaleFactor, wxPoint centre );
+
     /**
      * Function unitsChangeRefresh
      * is called when when the units setting has changed to allow for any derived classes

pagelayout_editor/pl_editor_frame.cpp

@@ -277,25 +277,15 @@ void PL_EDITOR_FRAME::OnCloseWindow( wxCloseEvent& Event )
 
 double PL_EDITOR_FRAME::BestZoom()
 {
-    int    dx, dy;
-    wxSize size;
+    double  sizeX = (double) GetPageLayout().GetPageSettings().GetWidthIU();
+    double  sizeY = (double) GetPageLayout().GetPageSettings().GetHeightIU();
+    wxPoint centre( sizeX / 2, sizeY / 2 );
 
-    dx = GetPageLayout().GetPageSettings().GetWidthIU();
-    dy = GetPageLayout().GetPageSettings().GetHeightIU();
+    // The sheet boundary already affords us some margin, so add only an
+    // additional 5%.
+    double margin_scale_factor = 1.05;
 
-    size = m_canvas->GetClientSize();
-
-    // Reserve no margin because best zoom shows the full page
-    // and margins are already included in function that draws the sheet refernces
-    double margin_scale_factor = 1.0;
-    double zx =(double) dx / ( margin_scale_factor * (double)size.x );
-    double zy = (double) dy / ( margin_scale_factor * (double)size.y );
-
-    double bestzoom = std::max( zx, zy );
-
-    SetScrollCenterPosition( wxPoint( dx / 2, dy / 2 ) );
-
-    return bestzoom;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre );
 }
 
 

pcbnew/append_board_to_current.cpp

@@ -207,7 +207,7 @@ bool PCB_EDIT_FRAME::AppendBoardFile( const wxString& aFullFileName, int aCtl )
     GetBoard()->SynchronizeNetsAndNetClasses();
 
     SetStatusText( wxEmptyString );
-    BestZoom();
+    Zoom_Automatique( false );
 
     // Finish block move command:
     wxPoint cpos = GetNearestGridPosition( bbox.Centre() );

pcbnew/files.cpp

@@ -533,7 +533,7 @@ bool PCB_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
         loadedBoard->SynchronizeNetsAndNetClasses();
 
         SetStatusText( wxEmptyString );
-        BestZoom();
+        Zoom_Automatique( false );
 
         // update the layer names in the listbox
         ReCreateLayerBox( false );

pcbnew/footprint_edit_frame.cpp

@@ -532,6 +532,21 @@ void FOOTPRINT_EDIT_FRAME::SaveSettings( wxConfigBase* aCfg )
 }
 
 
+double FOOTPRINT_EDIT_FRAME::BestZoom()
+{
+    EDA_RECT    ibbbox  = GetBoardBoundingBox();
+
+    double sizeX = (double) ibbbox.GetWidth();
+    double sizeY = (double) ibbbox.GetHeight();
+
+    wxPoint centre = ibbbox.Centre();
+
+    // Reserve a 20% margin around "board" bounding box.
+    double margin_scale_factor = 1.2;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre );
+}
+
+
 void FOOTPRINT_EDIT_FRAME::OnCloseWindow( wxCloseEvent& Event )
 {
     if( GetScreen()->IsModify() )

pcbnew/footprint_edit_frame.h

@@ -64,6 +64,8 @@ public:
     void LoadSettings( wxConfigBase* aCfg ) override;
     void SaveSettings( wxConfigBase* aCfg ) override;
 
+    double BestZoom() override;
+
     /**
      * Function GetConfigurationSettings
      * returns the footpr�int editor settings list.

pcbnew/footprint_viewer_frame.cpp

@@ -294,7 +294,7 @@ FOOTPRINT_VIEWER_FRAME::FOOTPRINT_VIEWER_FRAME( KIWAY* aKiway, wxWindow* aParent
 
     // Now Drawpanel is sized, we can use BestZoom to show the component (if any)
 #ifdef USE_WX_GRAPHICS_CONTEXT
-    GetScreen()->SetZoom( BestZoom() );
+    GetScreen()->SetScalingFactor( BestZoom() );
 #else
     Zoom_Automatique( false );
 #endif

pcbnew/footprint_wizard_frame.cpp

@@ -211,7 +211,7 @@ FOOTPRINT_WIZARD_FRAME::FOOTPRINT_WIZARD_FRAME( KIWAY* aKiway,
 
     // Now Drawpanel is sized, we can use BestZoom to show the component (if any)
 #ifdef USE_WX_GRAPHICS_CONTEXT
-    GetScreen()->SetZoom( BestZoom() );
+    GetScreen()->SetScalingFactor( BestZoom() );
 #else
     Zoom_Automatique( false );
 #endif

pcbnew/pcb_base_frame.cpp

@@ -322,21 +322,16 @@ EDA_RECT PCB_BASE_FRAME::GetBoardBoundingBox( bool aBoardEdgesOnly ) const
 
 double PCB_BASE_FRAME::BestZoom()
 {
-    if( m_Pcb == NULL )
-        return 1.0;
-
     EDA_RECT    ibbbox  = GetBoardBoundingBox();
-    DSIZE       clientz = m_canvas->GetClientSize();
-    DSIZE       boardz( ibbbox.GetWidth(), ibbbox.GetHeight() );
-
-    double iu_per_du_X = clientz.x ? boardz.x / clientz.x : 1.0;
-    double iu_per_du_Y = clientz.y ? boardz.y / clientz.y : 1.0;
 
-    double bestzoom = std::max( iu_per_du_X, iu_per_du_Y );
+    double  sizeX = (double) ibbbox.GetWidth();
+    double  sizeY = (double) ibbbox.GetHeight();
+    wxPoint centre = ibbbox.Centre();
 
-    SetScrollCenterPosition( ibbbox.Centre() );
+    // Reserve a 10% margin around board bounding box.
+    double margin_scale_factor = 1.1;
 
-    return bestzoom;
+    return bestZoom( sizeX, sizeY, margin_scale_factor, centre );
 }