How to refresh a GridView?
- by Daniel
Hello everyone,
I have a GridView which is pretty similar to the Google tutorial, except that I want to add the ImageViews on runtime (via a subactivity). The results are okay, but the layout of the View is messed up: The GridView doesn't fill the content of its parent, what do I have to do to design it properly?
Here the code of adding the children:
public void initializeWorkbench(GridView gv, Vector<String> items) {
Prototype.workbench.setDimension(screenWidth, divider.height()+workbenchArea.height());
Prototype.workbench.activateWorkbench();
// this measures the workbench correctly
Log.d(Prototype.TAG, "workbench width: "+Prototype.workbench.getMeasuredWidth());
// 320
Log.d(Prototype.TAG, "workbench height: "+Prototype.workbench.getMeasuredHeight());
// 30
ImageAdapter imgAdapter = new ImageAdapter(this.getContext(), items);
gv.setAdapter(imgAdapter);
gv.measure(screenWidth, screenHeight);
gv.requestLayout();
gv.forceLayout();
Log.d(Prototype.TAG, "gv width: "+gv.getMeasuredWidth());
// 22
Log.d(Prototype.TAG, "gv height: "+gv.getMeasuredHeight());
// 119
Prototype.workbench.setDimension(screenWidth, divider.height()+workbenchArea.height());
}
}
activateWorkbench, setDimension and measure in the workbench (LinearLayout above the GridView):
public void activateWorkbench() {
if(this.equals(Prototype.workbench)) {
this.setOrientation(VERTICAL);
show = true;
measure();
}
}
public void setDimension(int w, int h) {
width = w;
height = h;
this.setLayoutParams(new LinearLayout.LayoutParams(width, height));
this.invalidate();
}
private void measure() {
if (this.getOrientation() == LinearLayout.VERTICAL) {
int h = 0;
int w = 0;
this.measureChildren(0, 0);
for (int i = 0; i < this.getChildCount(); i++) {
View v = this.getChildAt(i);
h += v.getMeasuredHeight();
w = (w < v.getMeasuredWidth()) ? v.getMeasuredWidth() : w;
}
if (this.equals(Prototype.tagarea))
height = (h < height) ? height : h;
if (this.equals(Prototype.tagarea))
width = (w < width) ? width : w;
}
this.setMeasuredDimension(width, height);
}
The ImageAdapter constructor:
public ImageAdapter(Context c, Vector<String> items) {
mContext = c;
boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
// We can read and write the media
mExternalStorageAvailable = mExternalStorageWriteable = true;
} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
// We can only read the media
mExternalStorageAvailable = true;
mExternalStorageWriteable = false;
} else {
// Something else is wrong. It may be one of many other states, but
// all we need
// to know is we can neither read nor write
mExternalStorageAvailable = mExternalStorageWriteable = false;
}
if (mExternalStorageAvailable && mExternalStorageWriteable) {
for (String item : items) {
File f = new File(item);
if (f.exists()) {
try {
FileInputStream fis = new FileInputStream(f);
Bitmap b = BitmapFactory.decodeStream(fis);
bitmaps.add(b);
files.add(f);
} catch (FileNotFoundException e) {
Log.e(Prototype.TAG, "", e);
}
}
}
}
}
And the xml layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:gravity="bottom"
android:paddingLeft="0px"
android:paddingTop="0px"
android:paddingRight="0px">
<com.unimelb.pt3.ui.TransparentPanel
android:id="@+id/workbench"
android:layout_width="fill_parent"
android:layout_height="10px"
android:paddingTop="0px"
android:paddingLeft="0px"
android:paddingBottom="0px"
android:paddingRight="0px">
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center" />
</com.unimelb.pt3.ui.TransparentPanel>
</LinearLayout>
