ImageEn, unit imageenview




property MouseInteractLayers: TIEMouseInteractLayers;


An extension to MouseInteractGeneral for mouse activities related to layer editing and creation.

 Mouse interaction options are split into two properties: MouseInteractLayers and MouseInteractGeneral. Items of MouseInteractLayers relate only to layer editing and creation, whereas MouseInteractGeneral are all remaining options (selection, view, measurement and image editing functions)
 Multiple interactions can be specified, but activities that are not mutually compatible will be excluded
 Setting MouseInteractLayers, will also remove incompatible items from MouseInteractGeneral
 Use LayersResizeAspectRatio to control aspect ratio locking behaviour
 Layer interactions can not be set when the PdfViewer is enabled

Usage Notes

You can only select one of the following:
mlCreateImageLayers, mlCreateShapeLayers, mlCreateLineLayers, mlCreatePolylineLayers, mlCreateAngleLayers, mlCreateTextLayers,
mlClickCreateLineLayers, mlClickCreatePolylineLayers, mlDrawCreatePolylineLayers, mlClickCreateAngleLayers

The following are often used in combinations with others:
miZoom, miSmoothZoom, miDblClickZoom, miMovingScroll, mlEditLayerPoints,
mlMoveLayers, mlResizeLayers, mlRotateLayers (can be used with any of the miSelect* methods, except miSelectZoom). When miSelect and mlMoveLayer are specified together, then movement is only possible by clicking and dragging the edge of the current layer,
To use mlRotateLayers in combination with layer creation interactions (mlCreate*Layers), loShowRotationGrip must be included for LayerOptions
if mlEditLayerPoints and mlResizeLayers are used in combination, point layers will only be resizable by dragging their points


Demo  Demos\Other\MouseInteract\MouseInteract.dpr
Demo  Demos\LayerEditing\RotateLayers\RotateLayers.dpr
Demo  Demos\LayerEditing\Layers_AllTypes\Layers.dpr
Demo  Demos\LayerEditing\Layers_Lines\Layers.dpr

Compatibility Notes

Prior to v8.6.0, all mouse interactions (both MouseInteractGeneral and MouseInteractLayers items) were set with a single property MouseInteract. To overcome the size limitation for published sets, this was split into:

 MouseInteractGeneral: All mouse interactions that are not related to layer editing
 MouseInteractLayers: Mouse interactions for layer editing

In most cases, code that was previously:
ImageEnView1.MouseInteract := [ miZoom, miScroll ];

Simply changes to:
ImageEnView1.MouseInteractGeneral := [ miZoom, miScroll ];

However for layer editing items (miMoveLayers, miResizeLayers, miRotateLayers, miCreate*Layers, etc.), the prefix has changed to ml, and you must reference MouseInteractLayers.

In older versions:
ImageEnView1.MouseInteract := [ miMoveLayers, miResizeLayers ];

Now becomes:
ImageEnView1.MouseInteractLayers := [ mlMoveLayers, mlResizeLayers ];

These are the layer editing items: miMoveLayers, miResizeLayers, miRotateLayers, miCreateImageLayers, miCreateShapeLayers, miCreateLineLayers, miCreatePolylineLayers, miCreateTextLayers, miClickCreateLineLayers, miClickCreatePolylineLayers, miDrawCreatePolylineLayers, miEditLayerPoints
They are now named: mlMoveLayers, mlResizeLayers, mlRotateLayers, mlCreateImageLayers, mlCreateShapeLayers, mlCreateLineLayers, mlCreatePolylineLayers, mlCreateTextLayers, mlClickCreateLineLayers, mlClickCreatePolylineLayers, mlDrawCreatePolylineLayers, mlEditLayerPoints


// Allow users to create image layers. Prompt for an image file after selection
ImageEnView1.LayerOptions := ImageEnView1.LayerOptions + [ loAutoPromptForImage ];
ImageEnView1.MouseInteractLayers := [ mlCreateImageLayers ];

// Allow user to move and resize layers (allow multiple layer selection and ensure masks are moved with layers)
ImageEnView1.LayerOptions := ImageEnView1.LayerOptions + [ loAllowMultiSelect, loAutoSelectMask ];
ImageEnView1.MouseInteractLayers := [ mlMoveLayers, mlResizeLayers ];

A selected text layer with resize grips:

Four selected layers with resize grips:

// Allow user to rotate layers (allow multiple layer selection and ensure masks are moved with layers)
ImageEnView1.LayerOptions := ImageEnView1.LayerOptions + [ loAllowMultiSelect, loAutoSelectMask ];
ImageEnView1.MouseInteractLayers := [ mlRotateLayers ];

// Allow the user to create, size and rotate red arrows
ImageEnView1.LayerOptions := ImageEnView1.LayerOptions + [ loShowRotationGrip ];
ImageEnView1.MouseInteractLayers := [ mlCreateLineLayers, mlMoveLayers, mlResizeLayers, mlRotateLayers ];
ImageEnView1.LayerDefaults.Values[ IELP_LineColor ] := 'clRed';
ImageEnView1.LayerDefaults.Values[ IELP_LineWidth ] := '6';
ImageEnView1.LayerDefaults.Values[ IELP_LineShapeSize  ] := '20';
ImageEnView1.LayerDefaults.Values[ IELP_LineStartShape ] := '1';
ImageEnView1.LayerDefaults.Values[ IELP_Rotate ] := '235';

// Allow user to create star shapes at preferred aspect ratio
ImageEnView1.LayersResizeAspectRatio := iearAlways;
IEGlobalSettings().DefaultLayerShape := iesStar5;
ImageEnView1.MouseInteractLayers := [ mlCreateShapeLayers ];

// Allow user to draw a polygon
ImageEnView1.LayersAutoClosePolylines := iecmAlways;
ImageEnView1.MouseInteractLayers := [ mlClickCreatePolylineLayers ];

// Allow users to create and edit a polyline
ImageEnView1.LayersAutoClosePolylines := iecmManual;
ImageEnView1.MouseInteractLayers := [ mlClickCreatePolylineLayers, mlEditLayerPoints ];

// Allow users to edit a polyline. Hold Alt key to turn line into a curve
ImageEnView1.MouseInteractLayers := [ mlEditLayerPoints ];

// Allow users to draw rulers (lines with measurement values)
With ImageEnView1.LayerDefaults do
  Values[ IELP_RulerMode ]  := IntToStr( ord( iermLabel ));
  Values[ IELP_RulerUnits ] := IntToStr( ord( ieuCentimeters ));
  Values[ IELP_LabelPosition  ] := IntToStr( ord( ielpAutoAbove ));
  Values[ IELP_LineStartShape ] := IntToStr( ord( ieesBar ));
  Values[ IELP_LineEndShape   ] := IntToStr( ord( ieesBar ));
  Values[ IELP_LineWidth ] := '2';
IEGlobalSettings().MeasureDecimalPlaces := 1;
ImageEnView1.MouseInteractLayers := [ mlClickCreateLineLayers, mlEditLayerPoints ];

// Allow users to create text layers. Start in text editing mode (user can immediately begin typing text)
ImageEnView1.LayerOptions := ImageEnView1.LayerOptions + [ loAutoTextEditing ];
ImageEnView1.MouseInteractLayers := [ mlCreateTextLayers ];

// Add a star every time the layer clicks on the image (use OnNewLayer event to customize size)
ImageEnView1.LayerOptions := ImageEnView1.LayerOptions + [ loStampMode ];
IEGlobalSettings().DefaultLayerShape := iesStar5;
ImageEnView1.MouseInteractLayers := mlCreateShapeLayers;

// Allow user to make selections when there are multiple layers (current layer will be highlighted. Selecting a new layer will highlight and allow selection. Layer movement is possible by dragging the edge of the layer)
ImageEnView1.MouseInteractGeneral := [ miSelect, mlMoveLayers ];

// Allow user to make selections when there are multiple layers, including resizing and rotating layers. To move layers, you must drag and click the layer edge
ImageEnView1.MouseInteractGeneral := [ miSelect, mlMoveLayers, mlResizeLayers, mlRotateLayers ];

See Also