In my application I have an array of strings that I am trying to draw in a pop over. Previously, I have been able to draw images in the pop over, but trying to convert this to show text I have not been successful. Listed below is the function I just to get the images from the array, and draw them.
CGRect b = self.bounds;
CGFloat columnWidth = b.size.width / columnCount;
CGFloat rowHeight = b.size.height / rowCount;
for (NSUInteger rowIndex = 0; rowIndex < rowCount; rowIndex++) {
for (NSUInteger columnIndex = 0; columnIndex < columnCount; columnIndex++) {
CGRect r = CGRectMake(b.origin.x + columnIndex * columnWidth,
b.origin.y + rowIndex * rowHeight,
columnWidth, rowHeight);
UIImage *image = [self.colors objectAtIndex:rowIndex * columnCount + columnIndex];
[image drawInRect:r];
}
}
In this function (for the text, not the one above), the row and column count have sometimes changes - for the text display, columns is always 1, and the rows are always equal to the amount of items in the array (for our testing purposes, there is 1 string in the array currently) I have tried to make the image a UIlabel instead, and changing the test of the label to the item in the string - but it still does not display when using drawInRect. Does anyone have a solution to this? I basically need to find any way to draw this text in the rect, even if its not using a label and another method (like placing the text in an image, which I also was not able to figure out). Thanks for your help.
Related
I'm using UIScrollview in Xcode 4.6. I want to insert around 30 images into the scrollview. Within the storyboard I can't add this many as it doesn't actually let you scroll down on the storyboard to add more images, hence all the images overlap each other.
The answer is probably quite simple so sorry if this is a dumb question. How do I add this many images to the scrollview, is there a way to code it like in Android xml? Or is there anyway to not have the images overlap?
Also consider using a UITableView. It may be a more efficient way of handling that many images. You can load them as they're displayed, rather than all at once.
You won't want to do this in Interface Builder - that will make it a creation and maintenance nightmare.
Instead, do it in code. You'll want to Google UIScrollView tutorial to get started. It's really quite easy - much easier than dragging out a bunch of image views by hand.
So this is problem that I have solved before. There are a few ways that you could solve this I think the new preferred way at least in iOS 6.x you could opt to use UICollectionView.
UICollectionView View Apple Docs
This is a great tutorial site that has loads of helpful information
UICollectionView Tutorial
Also one solution I came up with was loading and placing the images manually. And then based on the size needed width wise I set my UIScrollView setcontentSize property.
//Clean Up and remove old buttons
for(int i=0; i < _localButtonArray.count; i++){
[(CategoryButton*)[_localButtonArray objectAtIndex:i] removeFromSuperview];
}
[_localButtonArray removeAllObjects];
CGFloat baseX = 10,
X = 0,
Y = 0;
int xPadding = 20,
yPadding = 12,
index = 0,
maxRow = 4,
maxCol = 4,
colCount = 0;
CGRect buttonFrame;
buttonFrame.size.height = 137;
buttonFrame.size.width = 137;
buttonFrame.origin.y = X;
buttonFrame.origin.x = Y;
for(int i = 0;i < _localInfoArray.count ; i++){
id object = [_localInfoArray objectAtIndex:i];
if(index >= maxRow){
index = 0;
X = baseX;
Y += buttonFrame.size.height + yPadding;
if(colCount >= (maxRow * maxCol)){
colCount=0;
baseX += 637;
Y = 0;
}
}
X = baseX + (index * (buttonFrame.size.width + xPadding));
index++;
colCount++;
buttonFrame.origin.x = X;
buttonFrame.origin.y = Y + yPadding;
/*
* Custom button class
*/
CategoryButton * categoryButton = [[CategoryButton alloc]initWithFrame:buttonFrame Object:object];
//Add action
[categoryButton addTarget:self action:#selector(categoryButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[categoryButton.titleLabel setNumberOfLines:3];
[categoryButton.titleLabel setLineBreakMode:NSLineBreakByWordWrapping];
[categoryButton.titleLabel setFont:[UIFont fontWithName:#"Helvetica-Bold" size:19]];
[categoryButton.titleLabel setTextAlignment:NSTextAlignmentCenter];
[categoryButton setMultipleTouchEnabled:NO];
[_localButtonArray addObject:categoryButton];
[self.view addSubview:categoryButton];
}
There is a lot of other code that isn't here, but laying out the page is handled here.
Even this isn't an optimal solution, but hopefully it will help you.
Best of luck ^_^
I have a few functions that I'm using to draw different type of text. For example:
- (CGFloat)drawInformation:(CGContextRef)c withLeftCol:(NSArray *)leftCol rightcol:(NSArray *)rightCol atPoint:(CGPoint)point withLineSpacing:(CGFloat)lineSpacing {
CGContextSetStrokeColorWithColor(c, [UIColor blackColor].CGColor);
CGFloat fontSize = 16.0;
UIFont *pFont = [UIFont fontWithName:#"Arial-BoldMT" size:fontSize];
CGFloat yOffset = 0;
for (NSString *leftColStr in leftCol) {
[leftColStr drawAtPoint:CGPointMake(point.x, point.y + yOffset) withFont:pFont];
yOffset += lineSpacing;
}
yOffset = 0;
for (NSString *rightColStr in rightCol) {
[rightColStr drawAtPoint:CGPointMake(rtStart, point.y + yOffset) withFont:pFont];
yOffset += lineSpacing;
}
return [leftCol count] > [rightCol count] ? [leftCol count] * (fontSize + lineSpacing) : [rightCol count] * (fontSize + lineSpacing);
}
I didn't include the whole method, but this is the gist of it. I basically take in an array of text, and draw them in two columns. I want to return the height of the area so I know how large it is and can draw the next piece of text below it.
One thing I found is even though I set my fontSize = 16, if I do a [#"text" sizeWithFont:pFont], I actually get 18 or something. As you can see, I add in some lineSpacing as well. So what I'm wondering is if I'm returning the correct amount in this case, and also, if I should be using the fontSize, or the [#"text" sizeWithFont:pFont].height in my return statement. In its current state, when I need to draw my next block of text at the new point, it is pretty off, like 100 points, and I'm not sure why there is such a discrepancy. Thanks!
Create separate variables for the y offset in your first loop and the y offset in your second loop. Then return MAX(yOffsetLeftCol, yOffsetRightCol).
I'm just getting started with iOS development. I would like to create a view that would contain 2 rows of image thumbnails as a preview. It would scroll horizontally. I'm wondering if the best approach would be to use 2 scrollviews or place them in a tableview with 2 rows.
If your thumbnail images and rows are essentially static, your best bet might be to drop your thumbnail image views directly into your scrollView. You can layout your thumbnail subviews into two rows and as many columns as necessary with some arbitrary calculations and avoid the need to use a UITableView (which works very well for scrolling rows, but doesn't natively support columns, and as a tool isn't imo the best for this particular job).
If you do elect to use a UITableView, I would put it into a single UIScrollview.... Unless you specifically seek two discretely scrolling rows, I wouldn't implement this with two UIScrollViews.
Here is a code snippet that suggests an approach. Consider 1)All subviews should be the same size 2)The subviews will "grid" themselves according to the bounds of the containing view. I wrote this snippet for a regular UIView (not a UIScrollView), but the concept will be the same: Consider size of scrollContent. Consider how many subviews will fit horizontally, and how many will fit vertically (hence, if you want 2 rows, the scroll view height should be just high enough to fully encompass the height of a single subview * 2):
- (void)layoutSubviews
{
//Lays out subviews in a grid to fill view.
float myWidth = self.bounds.size.width;
float myHeight = self.bounds.size.height;
if ([[self subviews] count] < 1)
{
return; //no subviews, must be added before layoutSubviews is called.
}
CGRect aSubviewRect = [[[self subviews] objectAtIndex:0] frame];
int numberOfColumns = (int)(myWidth / aSubviewRect.size.width);
float actualColumnWidth = myWidth / (float)numberOfColumns;
CGFloat paddingPerColumn = (actualColumnWidth - aSubviewRect.size.width);
int maxRows = (int)(myHeight / aSubviewRect.size.height);
int qtyOfViews = [[self subviews] count];
int numberOfRows = (qtyOfViews / numberOfColumns);
if ((qtyOfViews % numberOfColumns) > 0) //we need remainder row
{
++numberOfRows;
}
if (numberOfRows > maxRows)
{
numberOfRows = maxRows;
NSLog(#"More rows required than fit.");
}
float actualRowHeight = myHeight / (float)numberOfRows;
CGFloat paddingPerRow = (actualRowHeight - aSubviewRect.size.height);
for (UIView *aSubview in [self subviews])
{
int viewIndex = [[self subviews] indexOfObject:aSubview];
int rowIndex = (viewIndex / numberOfColumns);
CGFloat yOrigin = (roundf(((float)rowIndex * aSubviewRect.size.height) + (((rowIndex + 1) * paddingPerRow) / 2)));
int columnIndex = (viewIndex % numberOfColumns);
CGFloat xOrigin = (roundf(((float)columnIndex * aSubviewRect.size.width) + (((columnIndex + 1) * paddingPerColumn) / 2)));
CGRect frame = [aSubview frame];
frame.origin.y = yOrigin;
frame.origin.x = xOrigin;
[aSubview setFrame:frame];
}
}
I am writing a game in which a Uiimageview needs to be 'spawned,' if you will. every time the character hits the end box. Everything else is working except that. Could someone check my code and see what I'm doing wrong? Thanks!
for (int i = 1; i <= level; i++) {
int xPos = rand() % 316;
int yPos = rand() % 450;
UIImageView *mine = [[UIImageView alloc] initWithFrame:CGRectMake(xPos, yPos, 10, 10)];
}
You are not adding the views that you create in a loop as subviews to your main view. That's why they do not become visible.
As a side note, I think you would be better off using CALayer objects instead of UIImageView: they are lighter-weight, and require about the same amount of work.
Is there a way of getting the position (CGPoint) of the cursor (blinking bar) in an UITextView (preferable relative to its content). I don’t mean the location as an NSRange. I need something around:
- (CGPoint)cursorPosition;
It should be a non-private API way.
Requires iOS 5
CGPoint cursorPosition = [textview caretRectForPosition:textview.selectedTextRange.start].origin;
Remember to check that selectedTextRange is not nil before calling this method. You should also use selectedTextRange.empty to check that it is the cursor position and not the beginning of a text range. So:
if (textview.selectedTextRange.empty) {
// get cursor position and do stuff ...
}
SWIFT 4 version:
if let cursorPosition = textView.selectedTextRange?.start {
// cursorPosition is a UITextPosition object describing position in the text (text-wise description)
let caretPositionRectangle: CGRect = textView.caretRect(for: cursorPosition)
// now use either the whole rectangle, or its origin (caretPositionRectangle.origin)
}
textView.selectedTextRange?.start returns a text position of the cursor, and we then simply use textView.caretRect(for:) to get its pixel position in textView.
It's painful, but you can use the UIStringDrawing additions to NSString to do it. Here's the general algorithm I used:
CGPoint origin = textView.frame.origin;
NSString* head = [textView.text substringToIndex:textView.selectedRange.location];
CGSize initialSize = [head sizeWithFont:textView.font constrainedToSize:textView.contentSize];
NSUInteger startOfLine = [head length];
while (startOfLine > 0) {
/*
* 1. Adjust startOfLine to the beginning of the first word before startOfLine
* 2. Check if drawing the substring of head up to startOfLine causes a reduction in height compared to initialSize.
* 3. If so, then you've identified the start of the line containing the cursor, otherwise keep going.
*/
}
NSString* tail = [head substringFromIndex:startOfLine];
CGSize lineSize = [tail sizeWithFont:textView.font forWidth:textView.contentSize.width lineBreakMode:UILineBreakModeWordWrap];
CGPoint cursor = origin;
cursor.x += lineSize.width;
cursor.y += initialSize.height - lineSize.height;
return cursor;
}
I used [NSCharacterSet whitespaceAndNewlineCharacterSet] to find word boundaries.
This can also be done (presumably more efficiently) using CTFrameSetter in CoreText, but that is not available in iPhone OS 3.1.3, so if you're targeting the iPhone you will need to stick to UIStringDrawing.
Yes — as in there's a method to get the cursor position. Just use
CGRect caretRect = [textView rectContainingCaretSelection];
return caretRect.origin;
No — as in this method is private. There's no public API for this.
I try to mark a selected text, i.e. I receive a NSRange and want to draw a yellow rectangle behind that text. Is there another way?
I can advise you some trick:
NSRange selectedRange = myTextView.selectedRange;
[myTextView select:self];
UIMenuController* sharedMenu = [UIMenuController sharedMenuController];
CGRect menuFrame = [sharedMenu menuFrame];
[sharedMenu setMenuVisible:NO];
myTextView.selectedRange = selectedRange
Using this code, you can know get the position of the cut/copy/past menu and there place your yellow rectangle.
I did not find a way to get the menu position witout forcing it to appear by a simulated select operation.
Regards
Assayag
Take a screenshot of the UITextView, then search the pixel data for colors that match the color of the cursor.
-(CGPoint)positionOfCursorForTextView:(UITextView)textView {
//get CGImage from textView
UIGraphicsBeginImageContext(textView.bounds.size);
[textView.layer renderInContext:UIGraphicsGetCurrentContext()];
CGImageRef textImageRef = UIGraphicsGetImageFromCurrentImageContext().CGImage;
UIGraphicsEndImageContext();
//get raw pixel data
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
uint8_t * textBuffer = (uint8_t*)malloc(Width * Height * 4);
NSUInteger bytesPerRow = 4 * Width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(textBuffer, Width, Height,
bitsPerComponent, bytesPerRow, colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, Width, Height), textImageRef);
CGContextRelease(context);
//search
for(int y = 0; y < Height; y++)
{
for(int x = 0; x < Width * 4; x += 4)
{
int red = textBuffer[y * 4 * (NSInteger)Width + x];
int green = textBuffer[y * 4 * (NSInteger)Width + x + 1];
int blue = textBuffer[y * 4 * (NSInteger)Width + x + 2];
int alpha = textBuffer[y * 4 * (NSInteger)Width + x + 3];
if(COLOR IS CLOSE TO COLOR OF CURSOR)
{
free(textBuffer);
CGImageRelease(textImageRef);
return CGPointMake(x/4, y);
}
}
}
free(textBuffer);
CGImageRelease(textImageRef);
return CGPointZero;
}