public class

ImageView

extends View
java.lang.Object
   ↳ android.view.View
     ↳ android.widget.ImageView
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

Displays an arbitrary image, such as an icon. The ImageView class can load images from various sources (such as resources or content providers), takes care of computing its measurement from the image so that it can be used in any layout manager, and provides various display options such as scaling and tinting.

Summary

Nested Classes
public class ImageView.ScaleType Options for scaling the bounds of an image to the bounds of this view. 
XML Attributes
Attribute Name Related Method Description
android:adjustViewBounds setAdjustViewBounds(boolean) Set this to true if you want the ImageView to adjust its bounds to preserve the aspect ratio of its drawable. 
android:cropToPadding If true, the image will be cropped to fit within its padding

Must be a boolean value, either "true" or "false". 

android:maxHeight setMaxHeight(int) An optional argument to supply a maximum height for this view. 
android:maxWidth setMaxWidth(int) An optional argument to supply a maximum width for this view. 
android:scaleType setScaleType(ImageView.ScaleType) Controls how the image should be resized or moved to match the size of this ImageView. 
android:src setImageResource(int) Sets a drawable as the content of this ImageView. 
android:tint setColorFilter(int,PorterDuff.Mode) Set a tinting color for the image

Must be a color value, in the form of "#rgb", "#argb", "#rrggbb", or "#aarrggbb". 

[Expand]
Inherited XML Attributes
From class android.view.View
[Expand]
Inherited Constants
From class android.view.View
Public Constructors
ImageView(Context context)
ImageView(Context context, AttributeSet attrs)
ImageView(Context context, AttributeSet attrs, int defStyle)
Public Methods
final void clearColorFilter()
int getBaseline()

Return the offset of the widget's text baseline from the widget's top boundary.

Drawable getDrawable()
Return the view's drawable, or null if no drawable has been assigned.
Matrix getImageMatrix()
Return the view's optional matrix.
ImageView.ScaleType getScaleType()
Return the current scale type in use by this ImageView.
void invalidateDrawable(Drawable dr)
Invalidates the specified Drawable.
int[] onCreateDrawableState(int extraSpace)
Generate the new Drawable state for this view.
void setAdjustViewBounds(boolean adjustViewBounds)
Set this to true if you want the ImageView to adjust its bounds to preserve the aspect ratio of its drawable.
void setAlpha(int alpha)
void setColorFilter(ColorFilter cf)
Apply an arbitrary colorfilter to the image.
final void setColorFilter(int color, PorterDuff.Mode mode)
Set a tinting option for the image.
void setImageBitmap(Bitmap bm)
Sets a Bitmap as the content of this ImageView.
void setImageDrawable(Drawable drawable)
Sets a drawable as the content of this ImageView.
void setImageLevel(int level)
Sets the image level, when it is constructed from a LevelListDrawable.
void setImageMatrix(Matrix matrix)
void setImageResource(int resId)
Sets a drawable as the content of this ImageView.
void setImageState(int[] state, boolean merge)
void setImageURI(Uri uri)
Sets the content of this ImageView to the specified Uri.
void setMaxHeight(int maxHeight)
An optional argument to supply a maximum height for this view.
void setMaxWidth(int maxWidth)
An optional argument to supply a maximum width for this view.
void setScaleType(ImageView.ScaleType scaleType)
Controls how the image should be resized or moved to match the size of this ImageView.
void setSelected(boolean selected)
Changes the selection state of this view.
Protected Methods
void drawableStateChanged()
This function is called whenever the state of the view changes in such a way that it impacts the state of drawables being shown.
void onDraw(Canvas canvas)
Implement this to do your drawing.
void onMeasure(int widthMeasureSpec, int heightMeasureSpec)

Measure the view and its content to determine the measured width and the measured height.

boolean onSetAlpha(int alpha)
Invoked if there is a Transform that involves alpha.
boolean setFrame(int l, int t, int r, int b)
Assign a size and position to this view.
boolean verifyDrawable(Drawable dr)
If your view subclass is displaying its own Drawable objects, it should override this function and return true for any Drawable it is displaying.
[Expand]
Inherited Methods
From class android.view.View
From class java.lang.Object
From interface android.graphics.drawable.Drawable.Callback
From interface android.view.KeyEvent.Callback

XML Attributes

android:adjustViewBounds

Set this to true if you want the ImageView to adjust its bounds to preserve the aspect ratio of its drawable.

Must be a boolean value, either "true" or "false".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol adjustViewBounds.

android:cropToPadding

If true, the image will be cropped to fit within its padding

Must be a boolean value, either "true" or "false".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol cropToPadding.

Related Methods

android:maxHeight

An optional argument to supply a maximum height for this view. See {see android.widget.ImageView#setMaxHeight} for details.

Must be a dimension value, which is a floating point number appended with a unit such as "14.5sp". Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size), in (inches), mm (millimeters).

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol maxHeight.

Related Methods

android:maxWidth

An optional argument to supply a maximum width for this view. See {see android.widget.ImageView#setMaxWidth} for details.

Must be a dimension value, which is a floating point number appended with a unit such as "14.5sp". Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size), in (inches), mm (millimeters).

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol maxWidth.

Related Methods

android:scaleType

Controls how the image should be resized or moved to match the size of this ImageView.

Must be one of the following constant values.

ConstantValueDescription
matrix0
fitXY1
fitStart2
fitCenter3
fitEnd4
center5
centerCrop6
centerInside7

This corresponds to the global attribute resource symbol scaleType.

android:src

Sets a drawable as the content of this ImageView.

May be a reference to another resource, in the form "@[+][package:]type:name" or to a theme attribute in the form "?[package:][type:]name".

May be a color value, in the form of "#rgb", "#argb", "#rrggbb", or "#aarrggbb".

This corresponds to the global attribute resource symbol src.

Related Methods

android:tint

Set a tinting color for the image

Must be a color value, in the form of "#rgb", "#argb", "#rrggbb", or "#aarrggbb".

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol tint.

Public Constructors

public ImageView (Context context)

public ImageView (Context context, AttributeSet attrs)

public ImageView (Context context, AttributeSet attrs, int defStyle)

Public Methods

public final void clearColorFilter ()

public int getBaseline ()

Return the offset of the widget's text baseline from the widget's top boundary. If this widget does not support baseline alignment, this method returns -1.

Returns
  • the offset of the baseline within the widget's bounds or -1 if baseline alignment is not supported

public Drawable getDrawable ()

Return the view's drawable, or null if no drawable has been assigned.

public Matrix getImageMatrix ()

Return the view's optional matrix. This is applied to the view's drawable when it is drawn. If there is not matrix, this method will return null. Do not change this matrix in place. If you want a different matrix applied to the drawable, be sure to call setImageMatrix().

public ImageView.ScaleType getScaleType ()

Return the current scale type in use by this ImageView.

Related XML Attributes

public void invalidateDrawable (Drawable dr)

Invalidates the specified Drawable.

Parameters
dr the drawable to invalidate

public int[] onCreateDrawableState (int extraSpace)

Generate the new Drawable state for this view. This is called by the view system when the cached Drawable state is determined to be invalid. To retrieve the current state, you should use getDrawableState().

Parameters
extraSpace if non-zero, this is the number of extra entries you would like in the returned array in which you can place your own states.
Returns
  • Returns an array holding the current Drawable state of the view.

public void setAdjustViewBounds (boolean adjustViewBounds)

Set this to true if you want the ImageView to adjust its bounds to preserve the aspect ratio of its drawable.

Related XML Attributes
Parameters
adjustViewBounds Whether to adjust the bounds of this view to presrve the original aspect ratio of the drawable

public void setAlpha (int alpha)

public void setColorFilter (ColorFilter cf)

Apply an arbitrary colorfilter to the image.

Parameters
cf the colorfilter to apply (may be null)

public final void setColorFilter (int color, PorterDuff.Mode mode)

Set a tinting option for the image.

Related XML Attributes
Parameters
color Color tint to apply.
mode How to apply the color. The standard mode is SRC_ATOP

public void setImageBitmap (Bitmap bm)

Sets a Bitmap as the content of this ImageView.

Parameters
bm The bitmap to set

public void setImageDrawable (Drawable drawable)

Sets a drawable as the content of this ImageView.

Parameters
drawable The drawable to set

public void setImageLevel (int level)

Sets the image level, when it is constructed from a LevelListDrawable.

Parameters
level The new level for the image.

public void setImageMatrix (Matrix matrix)

public void setImageResource (int resId)

Sets a drawable as the content of this ImageView.

Related XML Attributes
Parameters
resId the resource identifier of the the drawable

public void setImageState (int[] state, boolean merge)

public void setImageURI (Uri uri)

Sets the content of this ImageView to the specified Uri.

Parameters
uri The Uri of an image

public void setMaxHeight (int maxHeight)

An optional argument to supply a maximum height for this view. Only valid if setAdjustViewBounds(boolean) has been set to true. To set an image to be a maximum of 100 x 100 while preserving the original aspect ratio, do the following: 1) set adjustViewBounds to true 2) set maxWidth and maxHeight to 100 3) set the height and width layout params to WRAP_CONTENT.

Note that this view could be still smaller than 100 x 100 using this approach if the original image is small. To set an image to a fixed size, specify that size in the layout params and then use setScaleType(ImageView.ScaleType) to determine how to fit the image within the bounds.

Related XML Attributes
Parameters
maxHeight maximum height for this view

public void setMaxWidth (int maxWidth)

An optional argument to supply a maximum width for this view. Only valid if setAdjustViewBounds(boolean) has been set to true. To set an image to be a maximum of 100 x 100 while preserving the original aspect ratio, do the following: 1) set adjustViewBounds to true 2) set maxWidth and maxHeight to 100 3) set the height and width layout params to WRAP_CONTENT.

Note that this view could be still smaller than 100 x 100 using this approach if the original image is small. To set an image to a fixed size, specify that size in the layout params and then use setScaleType(ImageView.ScaleType) to determine how to fit the image within the bounds.

Related XML Attributes
Parameters
maxWidth maximum width for this view

public void setScaleType (ImageView.ScaleType scaleType)

Controls how the image should be resized or moved to match the size of this ImageView.

Related XML Attributes
Parameters
scaleType The desired scaling mode.

public void setSelected (boolean selected)

Changes the selection state of this view. A view can be selected or not. Note that selection is not the same as focus. Views are typically selected in the context of an AdapterView like ListView or GridView; the selected view is the view that is highlighted.

Parameters
selected true if the view must be selected, false otherwise

Protected Methods

protected void drawableStateChanged ()

This function is called whenever the state of the view changes in such a way that it impacts the state of drawables being shown.

Be sure to call through to the superclass when overriding this function.

protected void onDraw (Canvas canvas)

Implement this to do your drawing.

Parameters
canvas the canvas on which the background will be drawn

protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec)

Measure the view and its content to determine the measured width and the measured height. This method is invoked by measure(int, int) and should be overriden by subclasses to provide accurate and efficient measurement of their contents.

CONTRACT: When overriding this method, you must call setMeasuredDimension(int, int) to store the measured width and height of this view. Failure to do so will trigger an IllegalStateException, thrown by measure(int, int). Calling the superclass' onMeasure(int, int) is a valid use.

The base class implementation of measure defaults to the background size, unless a larger size is allowed by the MeasureSpec. Subclasses should override onMeasure(int, int) to provide better measurements of their content.

If this method is overridden, it is the subclass's responsibility to make sure the measured height and width are at least the view's minimum height and width (getSuggestedMinimumHeight() and getSuggestedMinimumWidth()).

Parameters
widthMeasureSpec horizontal space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec.
heightMeasureSpec vertical space requirements as imposed by the parent. The requirements are encoded with View.MeasureSpec.

protected boolean onSetAlpha (int alpha)

Invoked if there is a Transform that involves alpha. Subclass that can draw themselves with the specified alpha should return true, and then respect that alpha when their onDraw() is called. If this returns false then the view may be redirected to draw into an offscreen buffer to fulfill the request, which will look fine, but may be slower than if the subclass handles it internally. The default implementation returns false.

Parameters
alpha The alpha (0..255) to apply to the view's drawing
Returns
  • true if the view can draw with the specified alpha.

protected boolean setFrame (int l, int t, int r, int b)

Assign a size and position to this view. This is called from layout.

Parameters
l Left position, relative to parent
t Top position, relative to parent
r Right position, relative to parent
b Bottom position, relative to parent
Returns
  • true if the new size and position are different than the previous ones

protected boolean verifyDrawable (Drawable dr)

If your view subclass is displaying its own Drawable objects, it should override this function and return true for any Drawable it is displaying. This allows animations for those drawables to be scheduled.

Be sure to call through to the super class when overriding this function.

Parameters
dr The Drawable to verify. Return true if it is one you are displaying, else return the result of calling through to the super class.
Returns
  • boolean If true than the Drawable is being displayed in the view; else false and it is not allowed to animate.